UNIVERSITY    OF    CALIFORNIA 

COLLEGE    OF    AGRICULTURE 

AGRICULTURAL   EXPERIMENT  STATION 

CIRCULAR  No.  276 

March,  1924 

HOME  CANNING 

By  W.  V.  CliUESS  and  A.  W.   CHRISTIE 


CONTENTS 


PAGE 

A.  Principles  of  Canning 2 

Causes  of  spoiling 2 

Methods  of  preserving 3 

Sterilizing  fruit  juices 4 

Preservatives 4 

Methods  of  home  canning 5 

B.  Methods,  Materials,  and  Equip- 

ment   5 

General  equipment 5 

Jars 6 

Cans 7 

Sealing  sanitary  cans 10 

Preparation  of  materials 11 

Packing  of  fruits 14 

Blanching 15 

Exhausting 15 

Syrups 15 

Brix  and  Balling  sugar  testers....  15 

Baum^  sugar  tester 16 

Strength  of  sjrups 16 

Cane  and  beet  sugar 17 

Brines 17 

Sterilizers 17 

Marking 19 

Storage  and  spoilage 19 

C.  Special  Directions  for  Fruits 20 

Apples 20 

Pears,  Peaches 20 

Apricots 21 


PAGE 

Plums,  Prunes 21 

Cherries 21 

Berries 21 

Grapes 23 

Figs 23 

Rhubarb 23 

Grape  Fruit 26 

Jelly  Juices 26 

Ripe  Olives 26 

D.  Special    Directions    for    Vege- 

tables   28 

Artichokes 28 

Asparagus 29 

Green    Beans 29 

Beets 30 

Sweet    corn 30 

Peas 30 

Peppers,    Pimientos 30 

Pumpkin 31 

Tomatoes 31 

Sweet   Potatoes 31 

Spinach 32 

Okra 32 

Soup  mixtures 32 

E.  Special  Directions  for  Meats 32 

F.  Ptomain  and  Botulinus  Poison- 

ing   34 

G.  Condensed  Directions 36 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


FOREWORD 

This  circular  is  based  on  Circular  No.  158,  "Home  and  Farm 
Canning, ' '  but  has  been  rearranged  and  almost  completely  rewritten. 
By  omitting  matters  of  interest  only  to  small  canneries,  and,  by  intro- 
ducing new  and  improved  methods  specially  adapted  to  the  home,  it 
has  been  made  more  suitable  for  its  primary  purpose.  The  writers 
desire  to  express  their  appreciation  to  Professor  F.  T.  Bioletti,  Dr. 
K.  F.  Meyer,  Dr.  W.  A.  Magoon,  Mr.  A.  Richardson,  and  others  for 
valuable  suggestions  given  during  the  preparation  and  revision  of  the 
manuscript. 

A.     PRINCIPLES  OF  CANNING 

Requests  for  information  on  the  home  canning  of  fruits  and 
vegetables  are  received  at  the  station  with  increasing  frequency.  To 
supply  this  information  it  has  been  found  necessary  to  test  the 
various  methods  generally  recommended.  This  has  been  done  both 
with  the  utensils  used  in  most  kitchens  and  with  special  canning 
equipment  constructed  for  home  and  small-scale  operations.  This 
circular  is  intended  to  describe  approved  methods  and  also  to  give 
general  information  asked  for  by  numerous  inquirers. 

A  large  quantity  of  fruits  and  vegetables  goes  to  waste  every  year 
or  is  sold  at  prices  which  return  little  profit.  Much  of  this,  while 
unsuited  to  the  special  requirements  of  the  commercial  cannery,  is 
well  adapted  to  canning  for  home  use.  The  quality  may  be  as  good 
as  that  of  the  products  of  commercial  canneries  or  better  if  put  up 
with  the  proper  knowledge  and  care.  It  is  often  possible  to  find  a 
limited  market  for  home  products  of  this  kind  at  profitable  prices. 

Local  and  private  markets  are  usually  the  most  satisfactory  for 
the  home  or  farm  canner.  He  will  seldom  find  it  profitable  to  sell  on 
the  general  market  through  dealers  in  competition  with  commercial 
canneries.  With  careful  attention  to  all  the  details  of  the  work  and 
a  little  business  ability  it  will  often  be  possible  to  make  the  home 
canning  outfit  a  profitable  adjunct  to  the  orchard  and  garden,  and 
much  of  the  work  will  be  found  agreeable  and  profitable  by  the  women 
of  the  household. 

Causes  of  Spoiling. — The  principal  aim  of  canning  is  to  prevent 
spoiling.  Spoiling  is  not  due  directly  to  the  action  of  air  or  of  heat 
and  it  is  not  simply  a  chemical  nor  a  physical  change.  When  vege- 
table materials  ferment,  decay  or  turn  sour,  it  is  because  of  the  growth 
of   certain   microscopic,   living  organisms,   or  '' germs. '*     These   all 


Circular  276]  HOME  CANNING  3 

belong  to  the  vegetable  kingdom  and  are  divided  into  three  groups: 
molds,  yeasts,  and  bacteria.  Familiar  examples  of  each  group  are 
the  blue-green  mold  of  spoiled  fruits,  the  yeast  used  in  bread-making, 
and  the  bacteria  of  the  scum  or  ''mother"  of  vinegar.  What  we  see 
in  compressed  yeast,  for  instance,  is  simply  a  mass  consisting  of 
millions  of  germs.  Individual  germs  are  too  minute  to  be  seen  with- 
out a  microscope.  Their  activities  cause  the  molding  of  jellies,  the 
swelling  and  souring  of  canned  fruits  and  vegetables,  and  the  putre- 
fying of  meats.  The  character  of  the  material  largely  determines 
which  type  of  spoiling  will  occur.  Acidity  is  favorable  to  yeasts  and 
molds.  Fruits  may  therefore  spoil  by  yeast  fermentation  or  become 
moldy.  Bacteria  prefer  a  medium  with  little  or  no  acid.  When  vege- 
tables or  meats  decay  it  is  therefore  usuallj'-  due  to  the  action  of 
bacteria.  Neither  fruits  nor  acid  vegetables  are  favorable  to  the 
growth  of  the  bacteria  which  cause  the  putrefaction  of  meats. 

Methods  of  Preserving. — The  micro-organisms  ("germs")  which 
cause  spoiling  come  from  the  air  or  from  the  surfaces  with  which  the 
material  comes  in  contact.  They  can  no  more  develop  from  non-living 
matter  than  wheat  can  appear  spontaneously  in  soil  devoid  of  wheat 
seed.  In  food  preservation,  we  are  dealing  with  living  organisms, 
whose  activities  can  be  prevented  in  one  of  two  ways :  We  may  kill  all 
the  germs  present  by  heat  or  other  means  and  prevent  the  entrance  of 
all  others,  or  we  may  make  the  conditions  so  unfavorable  to  the  germs 
that  they  cannot  grow  or  do  any  damage.  The  latter  way  is  followed 
when  we  impregnate  meat  with  so  much  salt  that  bacteria  cannot  grow, 
or  add  so  much  sugar  to  jam  that  yeast  cannot  multiply.  The  heat 
method  is  utilized  in  most  methods  of  canning. 

Sterilization  hy  Heat. — The  killing  of  all  germs  present  is  called 
sterilization.  In  canning,  this  is  accomplished  by  heating.  The 
material  to  be  preserved  is  placed  in  a  jar  or  can,  in  which  it  is  sealed 
hermetically,  i.e.,  made  air-tight.  It  is  then  heated  to  a  temperature 
fatal  to  all  the  germs  it  contains.  No  spoiling  can  then  take  place 
until  the  vessel  is  opened,  as  there  are  no  means  by  which  germs 
can  enter. 

Molds  and  yeasts,  as  they  occur  on  fruits  and  vegetables,  are 
quickly  killed  at  temperatures  below  212°  F.,  the  boiling  point  of 
water.  In  most  cases,  in  fact,  they  are  killed  at  temperatures  between 
150°  F.  and  180°  F.  On  the  other  hand,  bacteria  occurring  on 
vegetables  are  much  harder  to  kill,  many  of  them  withstanding  the 
temperature  of  boiling  water  for  several  hours.  These  bacteria  owe 
their  astonishing  resistance  to  the  presence  of  spores.  Spores  are  to 
bacteria  what  seeds  are  to  higher  plants  and  are  resistant  to  heat. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

These  bacteria,  with  resistant  spores,  probably  occur  also  on  fruits, 
but  it  is  usually  not  necessary  to  kill  them  in  this  case,  as  they  are 
very  sensitive  to  acidity  and  therefore  cannot  grow  in  fruit  juices. 
With  vegetables  the  case  is  different.  These,  with  the  exception  of 
tomatoes,  have  little  or  no  acidity  and  are  well  suited  to  the  growth 
of  the  heat-resistant  bacteria.  To  sterilize  vegetables  it  is  therefore 
usual  to  heat  the  sealed  cans  to  temperatures  above  212°  F.  The 
temperature  can  be  raised  to  212°  F.  by  placing  the  sealed  cans  in  an 
open  tank  or  pot  containing  boiling  water.  But  under  these  conditions 
no  higher  temperature  can  be  reached,  as  the  evolving  steam  removes 
the  excess  of  heat  as  fast  as  it  is  applied.  In  a  closed  space  where 
the  steam  cannot  escape,  however,  higher  temperatures  can  be 
obtained.  As  the  •  temperature  rises  the  pressure  increases.  In  can- 
ning vegetables,  pressures  of  five  to  fifteen  pounds  to  the  square  inch 
are  generally  used.  This  corresponds  to  temperatures  of  approxi- 
mately 227°  F.  to  249°  F.;  the  higher  the  pressure  the  higher  the 
temperature. 

Sterilizing  Fruit  Juices. — Heating  fruit  juices  to  212°  F.  always 
changes  the  flavor  more  or  less.  In  a  few  cases,  this  change  of  flavor 
may  be  an  improvement,  but  in  most  cases  it  is  desirable  to  retain 
as  much  of  the  original  character  of  the  juice  as  possible.  This  is 
accomplished  by  careful  handling  and  by  heating  to  the  lowest  tem- 
perature that  will  insure  sterilization.  Experiments  continued  for 
two  years  at  the  Fruit  Products  Laboratory  have  shown  that  most 
juices  can  be  safely  sterilized  at  temperatures  of  from  165°  to  175°  F. 
See  Circular  220,  Unfermented  Fruit  Juices,  for  details  of  prepara- 
tion. 

Preservatives. — Food  materials  can  be  prevented  from  spoiling  by 
the  use  of  certain  substances  known  as  preservatives.  Some  of  these 
are  injurious  to  health  and  forbidden  by  the  pure  food  laws.  Others 
are  not  encouraged  by  the  pure  food  laws,  because  they  are  used  by 
unscrupulous  manufacturers  to  disguise  defective  materials  or  care- 
less methods  of  manufacture.  The  use  in  canning  of  such  preserva- 
tives as  benzoate  of  soda,  salicylic  acid,  sodium  fluorid,  boric  acid, 
etc.,  is  condemned. 

Certain  preservatives,  however,  are  useful  and  permissible.  For 
fruits,  sugar  is  the  preservative  most  commonly  used.  If  the  sugar 
content  of  fruit  juice,  jelly  or  jam  is  raised  to  65  per  cent  by  evaporat- 
ing part  of  the  water,  or  by  adding  sugar,  these  products  become 
unsuitable  to  the  growth  of  microorganisms  and  will  keep  even  in 
open  vessels.  This  is  why  dried  fruit  does  not  spoil  and  why  jam 
must  be  made  very  sweet. 


Circular  276] 


HOME    CANNING 


For  some  products  salt  is  extensively  used,  as  in  preserving  olives 
in  barrels  and  in  keeping  certain  types  of  pickles.  Vinegar  and 
spices  are  used  in  the  same  way.  Sometimes  a  combination  of  the 
effects  of  heat  sterilization  and  harmless  preservatives  such  as  vinegar 
is  used  in  the  preserving  of  pickles,  etc. 

METHODS    OF    HOME    CANNING 

The  principles  and  theory  of  canning  are  the  same  whatever  the 
scale  on  which  it  is  done.  The  differences  are  only  in  the  mechanical 
details  of  the  methods  of  applying  these  principles. 

There  are  two  general  methods  in  use.  In  one,  known  as  the 
"Hot-pack  method,"  the  material  is  cooked  in  open  pots  and  poured 
into  the  cans  while  hot,  together  with  the  hot  brine  or  syrup.  The 
eans  are  sealed  immediately,  and  may  or  may  not  be  sterilized.  In 
the  other,  the  ''Cold-pack  method,"  the  freshly  prepared  material  is 
placed  cold  in  the  cans  and  then  covered  with  the  hot  syrup  or  brine, 
sealed  and  sterilized.  With  both  methods  the  material  is  always  hot 
when  the  cans  are  sealed.  The  cold-pack  method  is  generally  the  best 
for  vegetables,  while  the  hot-pack  method  can  often  be  used  to  advan- 
tage with  fruits,  if  supplemented  by  sterilization  in  the  container. 


B.     METHODS,  MATERIALS,  AND  EQUIPMENT 

General  Equipment. — Most  of  the  utensils  and  materials  needed  in 
home-canning  are  to  be  found  in  all  kitchens.  They  include  a  good 
stove,  or  other  means  of  heating,  a  table  for  the  preparation  of 
materials,  a  sink  and  good  supply  of  water,  various  agateware  or 
aluminum  pots,  saucepans,  and  buckets,  large  cooking  spoons  and  a 
sufficient  supply  of  sugar  and  salt.  To  these  should  be  added  a  good 
thermometer,  suitable  for  placing  in  liquids  and  reading  to  at  least 
250°  F.  (cost,  about  $1.50).  A  Balling  or  Brix  saccharometer  or 
sugar  tester  is  also  very  useful  where  fruit  is  to  be  canned  on  a  farm 
scale.  It  should  read  from  0  to  70  per  cent  and  costs  about  75  cents. 
For  use  with  this  will  be  needed  a  tin  cylinder  to  hold  the  liquids 
to  be  tested.  It  should  be  about  IV2  inches  in  diameter  and  about 
12  inches  long  (fig.  9).  The  thermometer  and  saccharometer  can 
often  be  obtained  through  a  drug  store  or  the  local  dealer. 

Other  necessary  or  desirable  materials  are  described  in  the  follow- 
ing paragraphs.  If  the  canning  is  to  be  done  on  a  somewhat  larger 
scale  for  the  market  it  will  often  be  advisable  to  purchase  a  factory- 
made  outfit  which  may  be  obtained  in  various  sizes. 


b  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Jars. — Glass  jars  are  preferable  to  tin  cans  for  home  canning  of 
fruits  because  they  can  be  used  repeatedly.  Their  greater  initial  cost 
is  offset  by  this  advantage.  Where  the  product  is  to  be  sold,  it  is 
usually  necessary  to  use  cans  unless  unusually  high  quality  is  de- 
manded and  a  price  sufficient  to  cover  the  extra  cost  of  jars  can  be 
obtained. 


Fig.  1. — Types  of  jars  used  in  home  canning:  (a)  Eemovable  clamp  and  glass 
top;  (h)  fixed  clamp  and  removable  glass  top;  (c)  lacquered  metal  clamp  top; 
(d)  wide  mouth  and  screw  top  of  lacquered  metal;  (e)  ordinary  narrow  mouth 
and  screw  top,  porcelain  or  glass-lined. 

Glass  jars  are  to  be  found  in  a  variety  of  sizes  and  shapes  and  with 
various  methods  of  hermetic  sealing.  The  sizes  most  used  are  pints 
and  quarts  and  to  a  smaller  extent  half -gallons.  The  only  important 
variation  in  shape  is  the  width  of  the  mouth  which  may  be  as  wide 
as  the  jar  or  only  about  half  its  width.  The  commonest  method  of 
sealing  is  by  means  of  a  rubber  ring  w^hich  fits  between  the  cover  and 
the  top  of  the  jar  (see  fig.  1). 

In  the  Mason  jar  and  its  various  modifications  the  cover  is  a  screw 
cap  which  makes  a  hermetic  joint  when  screwed  dow^n  on  the  rubber 
ring.  In  the  ordinary  form  this  cap  is  of  zinc  with  a  porcelain  lining. 
This  is  the  commonest  and  cheapest  form.  Aluminum  and  heavily 
lacquered  metal  caps  are  to  be  preferred  to  zinc  caps  because  of  the 
tendency  of  the  zinc  to  corrode  with  sour  fruits  and  tomatoes.  Wide- 
mouth  Mason  jars  are  now  made  which  are  very  convenient  for  large 
fruits.  However,  their  large  enameled  metal  caps  are  often  difficult 
to  remove  and  may  be  broken  in  opening  the  jar. 

In  another  common  form,  of  which  the  Atlas  '^E-Z"  seal  jar  is 
an  example,  the  cover  is  a  glass  disc  held  in  place  and  pressed  down 
on  the  rubber  by  means  of  a  strong  wire  clamp.     After  the  fruit 


Circular  276]  HOME  CANNING  .  7 

cools  the  clamp  may  be  removed  and  the  cover  will  be  held  in  place 
by  the  vacuum.  This  affords  a  convenient  means  of  detecting^  spoiled 
jars.  If  there  is  any  fermentation  of  the  fruit,  the  gas  formed  will 
fill  the  vacuum  and  the  cap  will  be  loosened.  This  is  a  very  convenient 
and  durable  form  of  cover  and  there  are  no  metal  parts  in  contact 
with  the  fruit. 

Vacuum  sealed  glass  jars  are  used  in  jelly  and  preserve  factories. 
They  have  enameled  metal  caps  resting  on  heavy,  soft  rubber  rings 
and  are  held  in  place  by  a  vacuum  inside  the  jars.  This  vacuum  is 
produced  by  means  of  an  expensive  machine.  For  home  use  some 
forms  of  these  jars  may  be  sealed  by  forcing  the  caps  on  by  hand, 
while  the  contents  are  hot.  On  cooling,  a  vacuum  is  produced  which 
holds  the  caps  firmly  in  place. 

In  all  cases  where  poor  rubbers  are  used  in  sealing  they  must  be 
specially  treated,  as  they  will  otherwise  give  a  disagreeable  taste  to 
the  food.  Fruit  and  vegetables  are  sometimes  completely  spoiled  by 
this  taste.  It  can  be  avoided  by  thoroughly  boiling  the  rubbers  in 
water  made  alkaline  with  two  or  three  teaspoons  of  washing  soda  to 
the  quart.  They  are  then  rinsed  and  boiled  a  second  time  in  water 
made  slightly  acid  with  lemon  juice  or  vinegar.  A  third  short  boiling 
in  plain  water  fits  them  for  use.  There  are  now  several  good  brands 
of  jar  rubbers  which  do  not  require  this  treatment.  They  can  be 
placed  directly  on  the  jars  from  the  package. 

In  some  forms  of  jars,  the  rubber  ring  is  replaced  by  a  ring  or 
disc  of  pasteboard  treated  or  varnished.  These  are  not  commonly 
used  and  are  less  generally  suitable. 

A  commoner  type  that  avoids  the  use  of  rubbers  is  the  Economy 
jar  and  its  modifications.  The  cover  is  an  enameled  metal  disc  around 
the  edge  of  which  runs  a  small  groove  filled  with  a  hard  wax-like  com- 
pound. When  the  jar  and  its  contents  are  heated  this  compound 
melts  and  seals  the  cover  to  the  jar  when  it  cools  and  hardens.  A 
metal  spring  holds  the  cover  in  place  until  the  compound  hardens  and 
may  then  be  removed.  This  is  jar  "c"  in  figure  1.  Considerable 
difficulty  has  been  met  in  using  this  jar  because  of  failure  of  the  caps 
to  seal  the  jars  perfectly. 

Cans. — There  are  three  general  types  of  cans  used  for  fruit  and 
vegetables — the  ''wax-top,"  the  ''solder-top,"  and  the  "sanitary." 

The  cover  of  the  "wax-top"  can  is  sealed  on  by  means  of  a  ring 
of  hot  sealing  wax.  It  is  suitable  for  use  with  fruits  and  tomatoes, 
but  it  is  not  satisfactory  for  vegetables  which  require  high  tem- 
peratures. The  cans  are  easily  manipulated  and  require  no  special 
equipment. 


8 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


''Solder-top"  or  ''stud-hole"  cans  with  the  necessary  soldering 
tools  are  used  in  the  factory-made  home  canning  outfits  and  can  be 
used  with  any  outfit.  The  top  of  the  can  has  a  circular  opening  vary- 
ing in  width  with  the  size  and  type  of  cans.  After  filling  the  can,  this 
opening  is  closed  by  soldering  on  a  tin  disc.  This  disc  is  usually 
perforated  with  a  small  hole  to  allow  steam  to  escape  during  the  pre- 
liminary heating.  This  hole  must  be  closed  with  solder  before  the 
final  sterilization.     (See  fig.  2,  G.) 


Fig.  2. — Types  of  cans  used  in  home  canning:  {A)  No.  1  tall  ''sanitary  can;  " 
{B)  No.  2  sanitary  can;  (C)  No.  2^/2  sanitary  can;  (D)  No.  3  sanitary  can; 
{E)  No.  10  sanitary  can;   {F)  quart  size  wax  top  can;    (G)  No.  2  solder  top  can. 

"Sanitary  cans"  used  in  large  canneries  are  not  sealed  with  solder. 
The  cover  or  cap  is  "crimped"  on  by  means  of  a  special  machine. 
There  is  a  rubber  coating  or  paper  gasket  on  the  cap  where  it  comes 
in  contact  with  the  can,  which  makes  the  sealing  doubly  sure.  Yqvj 
satisfactory  hand-power  machines  can  be  obtained  at  moderate  cost. 

Cans  may  be  obtained  which  are  coated  inside  with  a  protective 
enamel.  These  are  suitable  for  red  fruits,  berries  and  beets  as  they 
minimize  bleaching  of  the  red  color  through  action  of  the  tin. 

Cans  versus  Jars. — It  is  recommended  that  vegetables,  except 
tomatoes  and  rhubarb,  be  sterilized  under  steam  pressure  because  of 
the  danger  of  food  poisoning  from  those  heated  only  at  212°  F.  (in 
steam  or  boiling  water).  Unfortunately,  glass  jars  are  unsatisfactory 
for  use  in  a  pressure  sterilizer,  because  much  of  the  liquid  (brine  or 
syrup)  boils  out  of  the  container,  causing  the  jar  after  sterilization  to 
be  only  three-quarters  or  one-half  filled  with  liquid.     If  the  jars  are 


Circular  27G] 


HOME    CANNING 


tightly  sealed  to  avoid  this  difficulty,  many  of  them  will  })urst  or  many 
of  the  rubbers  will  be  forced  away  from  the  top,  causing  the  jar  to 
leak.  These  difficulties  are  overcome  in  commercial  canneries  by  the 
use  of  compressed  air  in  the  pressure  cookers,  but  this  is  not  feasible 
in  the  home. 


Fig.  3. — Small  hand  power  sealing  machine  for  sanitary  cans. 


We  have  found  that  sanitary  cans  are  the  only  satisfactory  con- 
tainers for  vegetables  to  be  sterilized  under  pressure  in  the  home. 
Where  the  quantity  of  vegetables  is  too  small  to  warrant  purchase 
of  a  can  sealer,  it  is  possible  for  several  families  to  join  in  the  pur- 
chase and  use  of  such  a  machine.    The  cost  is  approximately  $20.00. 


10 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 


Sealing  Sanitary"'  Cans. — Sanitary  cans  are  more  satisfactory  for 
home  use  than  solder  top  cans  for  several  reasons.  Very  little  experi- 
ence is  required  to  obtain  a  perfect  seal  with  the  hand  power  sealers 
used  for  sanitary  cans.  The  opening  of  the  can  is  wide,  permitting 
packing  of  large  pieces  of  fruit  or  vegetables.  The  cans  are  readily 
obtainable  from  can  manufacturers,  whereas  solder  top  cans  are  now 
difficult  to  obtain.  There  is  no  danger  of  fire  or  explosions  in  sealing 
sanitary  cans  because  the  gasoline  blow  torch  used  in  heating  soldering 
steels  is  not  used. 


/ 


firjt  OperAtion  Roll  Cao 


I  I 


^ 


firstOperjJionRoH' 


1 

1        1 

li 

1, 

llli 

IllMMUa^ 

1 

1    1 

1 

m\\\\\\\\\ 

■  "^ " 

r 

Second  Oporif 

on  RoU^ 

Fig.  4. — Sealing  a  sanitary  can.    (After  Cruess  and  Christie  Laboratory  Manual 
of  Fruit  and  Vegetable  Products.) 

1.  Lid  in  place  before  sealing. 

2.  Appearance  of  lid  and  edge  of  can  after  first  operation. 

3.  Appearance  after  second  operation. 


*  ' '  Sanitary "  is  a  trade  name  and  when  applied  to  this  type  of  can  does  not 
imply  that  other  cans  are  unsanitary. 


(JlKCLiLAR   276J  HOME   CANNING  11 

111  using  sanitary  cans  in  home  canning  tlie  prepared  food  is 
packed  into  the  washed  can  and  boiling  hot  syrup  or  brine  is  added 
to  fill  it.  In  commercial  canning  the  can  and  contents  are  heated 
in  live  steam  or  hot  water  for  4  to  10  minutes  before  sealing  in  order 
to  expel  air  from  the  food  and  liquid.  While  such  preliminary  heat- 
ing is  desirable  it  is  not  essential  in  home  canning,  provided  the  can 
is  filled  with  hoiling  hot  sprup  or  brine  and  sealed  at  once. 

The  general  appearance  and  method  of  using  a  hand  power  sani- 
tary can  sealer  are  shown  in  fig.  3.  To  use  the  sealer  proceed  as 
follows : 

{a)  Clamp  the  sealer  to  a  stout  table  top  as  shown  in  fig.  3.  Place 
the  lid  on  the  can  and  set  the  can  on  the  turn  table.  Raise  the  turn 
table  by  swinging  the  elevating  lever  from  the  operator  until  it  will  go 
no  farther. 

{!))  Turn  the  crank  rapidly  and  at  the  same  time  push  the  seam- 
ing roll  lever  very  slowly  away  from  the  operator  to  bring  the  roll 
number  one  against  the  top  of  the  can  until  it  will  go  no  farther. 
Fifteen  turns  of  the  crank  should  be  sufficient. 

(c)  Continue  turning  the  crank  rapidly  and  pull  the  seaming  roll 
lever  slowly  toward  the  operator  until  it  will  go  no  farther.  Give 
the  crank  several  more  turns  and  remove  the  sealed  can. 

Fig.  4  illustrates  the  top  of  the  can  before  sealing,  after  the  first 
seaming  operation  and  after  the  final  operation.  Sealing  a  sanitary 
can  is  spoken  of  as  "  double  seaming. ' ' 

Solder  top  cans  are  difficult  to  obtain  at  present  and  require  con- 
siderable skill  in  sealing.     They  are  not  recommended  for  home  use. 

PREPARATION    OF    MATERIALS 

Nearly  all  fruits  and  vegetables  require  some  kind  of  preparatory 
treatment  before  canning.  This  may  be  washing,  sizing,  sorting  for 
color  or  ripeness,  peeling,  pitting,  coring  or  slicing.  In  some  cases 
special  machines  or  tools  are  necessary.  Some  simple  tools  generally 
useful  are  show^n  in  figure  5.  These  are  {A)  a  knife  fitted  with  a 
guard  to  prevent  excessive  waste  of  pulp  in  peeling,  and  a  broad  knife 
{B)  for  cutting  and  slicing.  For  cling-stone  peaches  a  special  spoon 
(0)  with  sharp  edges  is  used.  A  curved  spoon  or  knife  (D)  is  used 
for  removing  the  cores  of  halved  pears.  Knife  (^)  is  used  for  coring 
apples.  A  cherry  pitter  is  very  useful.  -  See  figure  8.  Slicing  and 
cubing  machines  are  available  for  vegetables. 


12 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


The  Raw  Materials.— With  tlie  exception  of  pears,  fruits  for  can- 
ning are  best  if  tree  ripened  and  canned  as  promptly  after  picking 
as  possible.  Fruit  purchased  in  the  markets  of  large  cities  is  usually 
picked  immature.  It,  therefore,  is  of  poorer  flavor  than  that  which 
is  tree  ripened,  often  lacks  sugar,  and  may  be  more  or  less  wilted  or 
overripe.  City  housewives  will  rarely  find  such  fruit  either  economical 
in  price  or  equal  to  freshly  picked  ripe  fruit  in  quality. 


Fig.  5. — Knives  used  in  canning:    (A)  peeling  knife;    (B)  cutting  knife;    (6') 
peach  pitting  spoon;   (D)  pear  coring  knife;   (E)  apple  coring  knife. 


Vegetables  as  purchased  in  city  markets  are  usually  too  costly  for 
home  canning ;  commercially  canned  vegetables  are  much  cheaper. 
Vegetables  from  city  markets  are  apt  also  to  be  wilted  or  tough  because 
of  standing  after  harvesting.  Experience  and  experiments  have 
proven  that  such  material  is  more  difficult  to  sterilize  than  the  freshly 
picked  products,  because  of  contamination  with  resistant  bacterial 
spores,  and  therefore  more  liable  to  cause  food  poisoning  when  under- 


Circular  276]  HOME  CANNING  13 

sterilized.  Only  freshly  gathered  vegetables  from  the  home  or  farm 
garden  should  be  used  for  home  canning ;  for  reasons  of  quality, 
economy,  and  safety. 

Preparation  of  Fruits. — General  directions  applicable  to  more  than 
one  variety  of  fruit  may  most  conveniently  be  given  at  this  point. 

Sorting  and  Grading. — Moldy  and  soured  fruit  should  be  discarded 
— it  is  not  only  unfit  for  food  but  is  more  liable  to  develop  botulinus 
poison  if  improperly  sterilized. 

Overripe  but  sound  fruit  should  be  used  for  jam  rather  than  for 
canning. 

If  the  canned  product  is  to  be  sold,  it  should  be  carefully  graded 
for  size,  color,  and  maturity  into  two  or  three  grades.  These  may  be 
designated  First  Quality  (finest  and  most  nearly  perfect  specimens), 
Standard  Quality  (sound  fruit  of  fair  quality),  and  Pie  Fruit  (small, 
slightly  blemished,  or  overripe  fruit). 

Washing. — Clean  fruit  is  essential  to  success.  Wash  all  fruit 
thoroughly  before  canning. 

Hand  Peeling. — If  only  small  lots  of  fruit  are  to  be  canned,  hand 
peeling  is  the  most  practical  method.  A  guarded  knife  such  as  that 
shown  in  figure  5-A  is  desirable  for  soft  fruits  such  as  peaches  and 
pears,  while  the  knife  shown  in  figure  5-E  is  perhaps  most  satisfactory 
for  peeling  and  coring  apples. 

Mechanical  Peeling. — If  a  relatively  large  quantity  of  apples  is  to 
be  canned,  some  form  of  mechanical  peeler  is  desirable.  Hardware 
stores  can  supply  an  inexpensive  hand  power  peeler  for  kitchen  use. 
A  more  expensive  type  peels  and  cores,  or  peels,  cores,  and  slices  the 
apple  in  one  operation.  This  is  very  useful  for  preparing  apples 
for  drying. 

Mechanical  peelers  for  other  fruits  are  not  very  satisfactory. 

Lye  Peeling. — To  lye  peel  peaches  or  apricots,  first  prepare  in  an 
agate  ware  or  iron  kettle  (never  aluminum)  a  lye  solution  of  i/4  pound 
(4  ounces  or  about  4  level  tablespoons)  of  granulated  lye,  such  as 
Red  Seal  or  Rex  brands,  in  2  gallons  of  water.  Heat  to  boiling,  and 
while  actively  boiling  immerse  the  peaches  (halved  clings  or  whole 
freestones)  or  whole,  apricots  in  a  wire  basket  in  the  boiling  solution 
until  the  skin  is  loosened  and  i)artially  dissolved.  This  will  usually 
require  30  to  60  seconds.  Remove.  Wash  in  water  until  skin  and  lye 
are  removed.  Rinse  thoroughly  in  fresh  water.  Washing  away  the 
skin  and  lye  under  a  jet  of  water  from  a  faucet  is  nuicli  more  effective 
and  satisfactory  than  washing  in  still  water.     , 


14  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

It  will  not  be  found  worth  while  to  attempt  to  lye  peel  small  lots 
of  fruit,  but  the  method  will  save  a  great  deal  of  time  if  50  pounds 
of  fruit  or  more  is  to  be  peeled.  Lye  peeled  fruit  should  be  canned 
at  once  to  avoid  undue  darkening. 

Coring  and  Pitting. — Pears  are  peeled,  cut  in  half,  and  the  core 
is  then  removed  by  the  knife  shown  in  figure  5-D  or  by  means  of  a 
sharp  teaspoon. 

Dessert  cherries  are  usually  canned  without  pitting,  but  sour  or 
sweet  cherries  intended  for  use  in  pies  should  be  pitted  before  can- 
ning. A  mechanical  pitter,  such  as  that  shown  in  figure  8,  is  more 
convenient  than  the  small  pitters  operated  by  the  thumb  and  two 
fingers. 

Cling  peaches  are  difficult  to  pit  unless  the  spoon  shown  in  figure 
5-C  is  used.  To  use  this  spoon,  first  cut  the  peach  to  the  pit  com- 
pletely around  the  suture  ('* crease").  Insert  the  pitting  knife  (also 
known  as  pitting  spoon)  from  the  stem  end  of  the  peach  until  the 
point  of  the  spoon  rests  at  the  blossom  end  of  the  pit.  Rotate  the 
knife  until  one  half  of  the  peach  separates.  Then  scoop  the  pit  from 
the  other  half.    Pitting  is  best  done  before  peeling. 

Freestone  peaches  and  apricots  need  only  be  cut  in  half  and  the 
pit  removed  with  the  point  of  the  cutting  knife. 

Peeling  Vegetables. — Tomatoes  are  readily  peeled  after  immersion 
in  boiling  water  for  about  one  minute  and  chilling  in  cold  water.  The 
cores  should  be  removed  at  the  same  time,  but  if  possible  without 
opening  the  seed  sacs. 

Beets  require  about  10  to  15  minutes  boiling  to  loosen  the  skin ; 
sweet  potatoes  require  a  longer  time.  Other  root  vegetables  are  peeled 
by  hand  without  preliminary  heating. 

Mechanical  peelers  for  vegetables  are  too  costly  for  home  use. 

Packing  Fruit. — Most  fruits  may  be  packed  into  jars  or  cans  after 
preparation  and  without  previous  blanching  or  cooking.  They  should 
be  arranged  to  present  a  neat  appearance  in  the  jars. 

Some  fruits  soften  during  sterilizing  and  give  partially  filled 
containers,  unless  partially  cooked  before  packing.  Berries  for  this 
reason  should  be  cooked  with  an  equal  weight  of  sugar  before  packing. 
This  is  best  done  by  adding  the  dry  sugar  to  the  fruit  in  a  preserving 
kettle,  bringing  to  a  boil  and  boiling  gently  3-4  minutes.  The  juice 
of  the  fruit  forms  a  syrup  with  the  sugar — usually  an  excess  of  syrup 
unless  the  mixture  be  allowed  to  stand  overnight  to  permit  absorption 
of  the  syrup  by  the  fruit.  It  may  then  be  packed  and  sterilized  in 
the  jars  or  cans. 


CiKCULAR  27GJ  HOME   CANNING  15 

Apples  should  be  cooked  in  boiling  water  and  apricots  in  boiling 
dilute  syrup  3-4  minutes  to  soften  them  and  cause  shrinkage.  They 
may  then  be  packed  hot.  If  this  is  not  done,  the  jars  will  be  only 
partially  full  after  sterilization. 

All  fruits,  in  order  to  conserve  can  and  jar  space,  may  be  cooked 
a  short  time  with  sugar  and  a  small  amount  of  water  as  shown  in 
figure  9.  Some  home  canners  prefer  this  to  the  cold  pack  method. 
The  objection  to  it  is  that  some  fruits  become  broken  and  present  a 
less  attractive  appearance  than  cold  packed  fruit. 

Cold  packing  of  the  raw  fruit  is  recommended  for  peaches,  pears, 
plums,  prunes,  and  cherries. 

Blanching. —  Certain  vegetables  should  be  ''blanched"  or  parboiled 
before  canning.  This  is  done  by  dipping  them  in  boiling  water  or 
heating  in  steam.  A  wire  screen  basket  or  a  frying  basket,  such  as  is 
used  in  cooking  doughnuts,  will  serve  to  hold  the  vegetables  while  they 
are  dipped  in  a  large  cooking  pot  containing  boiling  water.  This 
treatment  improves  the  quality,  by  removing  slimy  matters  and  lessen- 
ing the  astringent  taste  of  the  skins.  It  is  necessary  with  asparagus  to 
remove  bitterness.  Blanching  also  softens  the  vegetables  so  that  a 
larger  amount  may  be  packed  into  the  jar  or  can. 

Apples  and  apricots  should  also  be  blanched  as  described  above  in 
order  that  a  full  can  may  be  obtained. 

Exhausting. — This  process  is  desirable  with  nearly  all  air-tight 
containers  which  are  to  be  sterilized  by  heat.  It  consists  of  a  prelim- 
inary heating  before  sealing  and  before  the  final  sterilization.  It 
results  in  expanding  the  air  inside  the  container  and  thus  driving  out 
most  of  it.  When  the  sealed  container  and  its  contents  cool,  the  small 
amount  of  air  still  enclosed  contracts  and  produces  a  partial  vacuum. 
If  cans  are  sealed  while  the  contents  are  cool  they  will  swell  on  heat- 
ing, owing  to  the  expansion  of  the  heated  air.  Exhausting  is  not 
necessary  with  jars.  If  cans  are  packed  with  hot  products,  boiling 
hot  syrup  or  brine  added  and  the  cans  sealed  at  once,  exhausting  can 
be  omitted  in  home  canning.  If  merely  warm  or  cold  brine  or  syrup 
is  added,  the  can  and  contents  should  be  heated  in  live  steam- or  boil- 
ing water  for  at  least  five  minutes  before  sealing. 

Syrups. — Fruits  are  canned  in  sugar  syrups  of  various  strengths  or 
concentrations.  In  general,  the  more  acid  fruits  require  the  most 
sugar.  The  appropriate  strengths  are  given  in  the  directions  for 
canning  the  various  fruits. 

Brix  or  Balling  Sugar  Testers. — Syrups  of  the  desired  strengths 
may  be  made  up  by  weighing  the  sugar  and  measuring  the  water, 
or  by  adding  sugar  to  the  water  until  the  desired  strength  is  indicated 


16 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


by  the  sugar  tester  or  hydrometer.  This  is  sometimes  called  a  sac- 
charometer  and  the  commonest  forms  are  the  Brix  and  the  Balling. 
The  hydrometer  is  floated  in  a  sample  of  the  syrup  contained  in  a  tall, 

narrow  metal  or  glass  cjdinder  and  the 
per  cent  of  sugar  read  from  the  scale  at 
the  surface  of  the  liquid.  If  the  syrup 
is  cold  the  reading  is  correct  enough  for 
the  purpose,  but  if  very  hot  the  reading 
may  be  several  per  cent  too  high.  (See 
fig.  6.) 

Baume  Sugar  Tester. — This  is  a 
hydrometer  similar  in  form  to  the  Brix, 
differing  only  in  the  scale,  which  reads 
in  degrees  instead  of  per  cent.  The  de- 
grees may  be  multiplied  by  two  to  give 
the  per  cent  approximately. 

Strength  of  Syrups, — For  all  prac- 
tical purposes  syrups  for  home  canning 
may  be  prepared  with  the  following  pro- 
portions of  sugar  and  water :  Light 
Syrup,  1  cup  sugar  to  4  cups  of  water; 
Medium,  1  cup  of  sugar  to  two  of  water ; 
and  Heavy,  1%  cups  of  sugar  to  1  of 
Avater. 

By  carefully  measuring  the  sugar 
and  water,  syrups  of  any  desired 
strength  can  be  made.  The  following 
table  shows  the  relation  between  the 
sugar  per  cent,  Brix  or  Balling,  the 
Baume  degree  and  the  proportion  of 
sugar  and  water: 


0  ^H 

19  mi 


Fig.  6. — Cylinder,  thermom- 
eter, and  Balling  sugar  tester. 
The  tester  in  the  cylinder  of 
syrup  is  read  at  the  surface  of 
the  liquid.  In  the  illustration 
this  is  approximately  12  per 
cent. 


SUGAE 

SYEUPS 

Per  cent  of  si 

igar 

Baume 

Weight  of  i 

iugar  added 

(Brix  or  Ball 

ng) 

degrees 

to  1  gal. 

of  water 

10 

5.5 

0 

lbs. 

15  oz. 

20 

11.0 

2 

2 

30 

16.5 

3 

10 

40 

22.0 

5 

10 

50 

27.0 

8 

6 

60 

32.5 

12 

10 

65 

35.0 

15 

11 

Circular  27()J  HOME   CANxVING  17 

In  making'  syrups  accordinji^  to  this  table,  the  weight  of  sugar  in 
the  last  two  columns  opposite  the  desired  per  cent  or  degree  is  added 
to  each  gallon  oi*  water  and  dissolved  by  warming  and  stirring.  The 
volume  of  syrup  obtained  is  greater  than  that  of  the  water  used.  The 
increase  of  volume  is  very  slight  with  syrups  of  5  to  15  per  cent,  but 
is  greater  with  more  concentrated  syrups ;  15  pounds  11  ounces  of 
sugar  and  1  gallon  of  water  giving  nearly  2  gallons  of  syrup  at  65 
per  cent.  For  one  quart  of  water  use  one-fourth  the  amounts  of  sugar 
noted  above. 

Cane  and  Beet  Sugar. — In  numerous  tests  made  by  the  Fruit 
Products  Laboratory,  beet  sugar  was  found  to  give  results  equal  to 
those  of  cane  sugar.  The  prejudice  against  beet  sugar  is  no  longer 
warranted  as  it  is  now  produced  in  as  pure  a  state  as  cane  sugar,  with 
which  it  is  identical  chemically.  Beet  sugar  is  equally  as  good  as  cane 
sug-ar  for  jellies  and  preserves  and  is  used  by  many  canners  and 
preservers. 

Adding  the  Syrup. — The  syrup  should  be  boiled,  strained  to 
remove  solid  impurities  and  poured  into  the  jar  or  can  boiling  hot. 

Brines. — For  most  canned  vegetables  a  brine  of  about  2  per  cent 
salt  is  used.  This  corresponds  to  about  21/2  ounces  or  about  5  level 
tablespoons  of  salt  per  gallon  of  water.  Unless  otherwise  directed, 
this  brine,  boiling  hot,  should  be  used  to  fill  all  cans  of  vegetables. 

Sterilizers. — A  sterilizer  is  a  vessel  in  which  the  filled  cans  or  jars 
are  heated  to  the  degree  and  for  the  time  necessary  to  sterilize  their 
contents. 

Sterilizer  for  212°  F. — The  sterilizer  containing  the  cans  and  sev- 
eral inches  of  water  is  placed  on  a  stove,  and  steam  generated  by 
boiling  the  water  heats  the  cans.  The  cover  must  be  sufficiently  close 
to  insure  steam  heat  in  all  parts  of  the  vessel,  but  must  not  be  too 
tight,  or  the  steam  pressure  will  cause  the  vessel  to  burst.  An 
ordinary  wash  boiler  fitting  the  top  of  a  kitchen  stove  can  be  made 
to  serve  as  a  very  satisfactory  home  sterilizer.  A  piece  of  heavy  wire 
screen  of  half -inch  mesh  or  a  wooden  rack  cut  to  fit  should  be  placed 
in  the  bottom.  This  will  serve  to  keep  the  jars  from  contact  with  the 
bottom  of  the  boiler,  where  they  might  break  if  too  close  to  the  fire. 
Inexpensive  jar  racks  to  be  used  in  wash  boiler  sterilizers  are  now 
obtainable  at  any  hardware  store.     Such  a  rack  is  shown  in  figure  9. 

Cans  may  be  placed  in  two  or  more  tiers,  separated  and  supported 
by  slat  gratings  w^hich  allow  the  steam  to  penetrate  to  all  parts  of 
every  can.  The  cover  of  the  boiler  should  fit  snugly  in  order  that 
the  steam  will  be  confined  and  heat  the  upper  part  of  the  sterilizer 


18  UNIVERSITY    OP    CALIFORNIA EXPERIMENT    STATION 

to  the  boiling  temperature.  A  cloth  should  be  placed  between  the 
cover  and  the  top  of  the  boiler  if  the  cover  does  not  fit  tightly.  See 
figure  10. 

Count  time  after  the  water  hoils. 

Pressure  Sterilizers. — Certain  vegetables  are  difficult  to  sterilize 
except  at  very  high  temperatures.  Sterilizers  using  high  pressure 
steam  will  attain  these  temperatures  and  the  cheapest  forms  can  be 
bought  for  about  $18.    See  figure  11. 

Where  vegetables  and  meat  are  to  be  canned  for  sale  it  will  usually 
pay  to  obtain  a  pressure  cooker,  as  they  are  fairly  easy  to  operate. 
Directions  for  operating  accompany  the  outfits. 

The  pressure  cooker  is  fitted  with  steam  gauge,  thermometer, 
release  cock  and  safety  valve  with  weight  and  lever  to  regulate  the 
pressure.  In  using  it  about  3  inches  of  hot  water  is  added.  The 
sealed  cans  are  then  placed  in  the  crate  and  lowered  into  the  sterilizer. 
The  cover  of  the  cooker  is  now  screwed  down,  but  the  release  cock  is 
left  open.  Heat  is  then  applied  until  steam  escapes  freely  from  the 
open  cock.  This  cock  is  then  closed  and  heating  continued  until  the 
temperature  reaches  the  desired  point.  At  this  point  the  safety  valve, 
weight  and  lever  should  be  set  for  the  corresponding  pressure.  At 
the  same  time  the  release  cock  is  opened  slightly,  so  as  to  allow  a 
small  escape  of  excess  steam.  By  this  means  the  temperature  can  be 
regulated  very  exactly.  The  safety  valve  will  open  and  relieve  the 
pressure  if  the  temperature  commences  to  go  too  high.  When  the 
heating  has  continued  for  the  required  time,  the  cooker  is  removed 
from  the  fire,  the  release  cock  opened  full,  and  when  the  pressure  has 
fallen  to  0  the  cans  are  removed  and  cooled  in  w^ater.  If  the  cooker 
is  opened  before  the  pressure  has  fallen  to  0,  steam  may  scald  the 
operator.  The  larger  outfits  of  this  kind  are  equipped  with  a  small 
steam  boiler  for  heating,  and  three  or  more  cookers.  Pressure  steril- 
izers are  usually  operated  at  5,  10,  or  15  pounds  pressure,  correspond- 
ing to  227°  F.,  239°  F.,  and  249°  F.,  respectively. 

Closing  and  Cooling  Jars  and  Cans. — After  the  sterilizing  period 
is  completed  in  the  212°  F.  sterilizer  or  after  the  pressure  in  the 
pressure  cooker  has  fallen  to  0,  with  the  release  valve  closed,  remove 
the  jars;  screw  or  clamp  the  tops  tightly  and  invert  jars  to  cool  in  a 
room  free  from  cold  drafts.  The  exceptions  to  this  rule  are  Economy 
and  similar  jars  with  composition  tops — clamp  the  tops  of  these 
tightly  but  do  not  invert. 

Cans  are  sealed  before  sterilization;  and  are  removed  and  chilled 
to  about  blood  temperature  in  cold  water  after  sterilization.     With 


Circular  276]  HOME  CANNING  19 

cans  the  release  valve  may  be  opened  immediately  after  the  steriliza- 
tion period  is  complete. 

Marking  Cans  and  Jars. — All  containers  should  be  plainly  marked 
with  the  variety  and  grade  of  the  product.  This  can  be  done  by  means 
of  a  small  set  of  rubber  stamps  and  canner's  ink,  which  will  stand 
hot  water.  They  may  also  be  marked  after  sterilization  with  gummed 
labels  or  wax  pencils  specially  made  for  writing  on  tin  and  glass. 
The  name  of  the  fruit  and  some  such  mark  as  A  or  1  for  first  and  B 
or  2  for  second  grade  on  the  bottom  of  the  can  will  serve  to  identify 
them.    India  ink  is  satisfactory  for  stamping  or  marking  cans. 

All  lots  should  be  dated  so  that  the  containers  of  each  lot  may  be 
identified  later,  and  a  short  record  giving  the  time  of  sterilization  in 
each  case  should  be  kept  for  future  reference.  Such  labeling  and 
records  will  be  found  very  valuable  in  locating  the  cause  of  spoilage, 
should  this  occur. 

Storage  and  Spoilage. — Before  any  canned  fruit  is  put  on  the 
market,  it  should  be  stored  at  least  a  month  to  see  if  it  will  show 
spoilage.  It  is  better  to  have  cans  spoil  in  the  storeroom  than  on  the 
grocers'  shelves.  If  the  fire  used  to  heat  the  sterilizer  is  not  hot 
enough,  it  may  take  too  long  to  bring  the  cans  to  the  temperature  of 
boiling  water  and  the  ''germs"  that  cause  spoilage  may  not  be  killed. 
Often,  however,  the  trouble  is  due  to  leaks  in  the  cans.  With  an 
inexperienced  operator,  leaks  often  occur  around  the  seam  of  sanitary 
cans  or  in  the  solder  groove  of  the  cap  of  solder  top  cans.  When  the 
capping  operation  is  well  done,  there  should  be  very  few  leaks.  Leaks 
can  be  detected  by  bubbles  appearing  when  the  cans  are  dropped  into 
hot  water.  Leaks  permit  air  to  enter  and  the  air  brings  with  it 
"germs"  which  cause  the  fruit  or  other  product  to  ferment  or  spoil 
and  produce  the  gas  that  causes  the  cans  to  swell.  Jars  should  be 
wrapped  in  paper  to  exclude  light  and  stored  in  a  cool  place. 

Spoiled  cans  or  jars  of  food  should  never  be  tasted  or  used.  They 
may  contain  Bacillus  hotulimis,  and  be  deadly  poisonous.  Do  not  feed 
spoiled  canned  food  to  fowls  or  animals — it  may  poison  them.  Many 
cases  of  poisoning  of  chickens  by  spoiled  home  canned  foods  are  on 
record.  See  also  discussion  of  Ptomain  and  Botulinus  poisoning, 
page  34. 


20  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


C.     SPECIAL  DIRECTIONS  FOR  FRUITS 

Apples. — Canned  apples  are  used  principally  for  pies.  Any  variety 
v^ill  do  for  this  purpose,  but  canners  in  California  are  limited  largely 
to  Bellflowers,  Newtown  Pippins,  and  Gravensteins,  as  these  are  the 
chief  varieties  grown  in  the  state  and  available  culls  are  chiefly  of 
these  varieties. 

Peel;  core;  quarter;  blanch  in  boiling  water  3-4  minutes;  pack 
hot;  fill  with  boiling  water,  and  process  as  directed  in  Table  1. 

Apple  Sauce. — Prepare  as  for  the  table.  Pack  scalding  hot  into 
cans.    Sterilize  as  for  apples. 

Pears. — The  Bartlett  is  the  best  variety  for  canning  purposes. 
Fruit  for  canning  is  harvested  while  still  green  but  after  it  has 
reached  full  size.  It  is  allowed  to  ripen  in  boxes.  When  canned,  it 
should  be  of  good  size  and  prime  ripe,  but  not  too  soft.  The  fruit  is 
peeled  by  hand  and  cored  by  the  coring  knife  shown  in  figure  5-D. 

As  pears  tend  to  turn  brown  rapidly  after  peeling,  they  should  be 
placed  in  the  can  with  syrup  as  soon  as  peeled,  or  should  be  kept  under 
water  or  dilue  brine  (2  tablespoons  of  salt  per  gallon  of  water)  after 
peeling  until  used.  Pack  into  jars  or  cans  and  add  hot  medium  or 
light  syrup.    See  Table  1  for  sterilization. 

Peaches. — For  canning,  peaches  must  have  a  good  flavor  which 
remains  after  heating ;  the  texture  must  be  close  and  the  fiber  tender ; 
the  color  should  be  an  even  yellow  and  the  ripening  uniform  from 
surface  to  pit.  Of  the  cling  varieties,  the  Tuscan  and  Phillips  are  very 
satisfactory,  and  of  the  freestones,  the  Lovell,  Muir,  Crawford,  and 
Elberta  are  preferred. 

Peel  and  pit  as  directed  on  page  11.  Pack  in  cans  or  jars  and 
add  hot  Medium  or  Heavy  syrup.  See  also  table  1  for  further 
directions. 

Peaches  may  be  canned  in  a  plain  syrup  or  in  a  sweet  spiced 
vinegar  made  as  follows : 

Sugar 3%  lbs 

Vinegar 1  pint 

Water 1  pint 

Ginger  root i/i  oz. 

Whole  cloves i^  oz. 

Stick   cinnamon %   oz. 

Bring  this  mixture  to  boiling.  Let  stand  over  night  to  absorb  spice 
flavor.     Strain  and  add  boiling  hot  to  the  jar  or  can. 

If  full  jars  or  cans  are  desired  the  fruit  may  be  prepared  and 
canned  as  directed  in  the  hot-pack  method  shown  in  figs.  9  and  10. 


Circular  276] 


HOME   CANNING 


21 


Apricots. — Apricots  for  canning  should  be  rix)e  and  well  colored, 
but  not  too  soft.  Many  canners  make  the  mistake  of  canning  apricots 
too  green.  The  canned  product  from  such  fruit  has  a  ''green" 
astringent  taste  that  no  amount  of  sugar  can  wholly  overcome.  If 
over-ripe,  on  the  other  hand,  the  fruit 
cooks  down  to  a  jam  of  unattractive 
appearance.  Blanching  for  3-4  minutes 
in  boiling  syrup  before  packing  is  de- 
sirable. 

Apricots  require  a  heavy  syrup  to 
bring  out  their  best  flavor.  See  table  1 
for  further  directions. 

Plums. — This  fruit  is  canned  whole. 
On  account  of  the  plum's  high  acidity, 
glass  is  to  be  preferred  to  tin. 

The  fruit  should  be  picked  when  it  is 
beginning  to  turn  soft.  If  too  ripe,  it 
will  cook  down  to  a  jam  in  the  can  and 
if  too  green  will  be  too  sour  and  lacking 
in  flavor.  Blanching,  as  with  apricots, 
before  canning  is  desirable.  Pack  in 
cans  or  jars  and  add  a  Medium  or 
Heavy  syrup.    See  also  table  1  for  sterilization. 

Fresh  Prunes. — Fresh  California  prunes  are  not  canned  commer- 
cially, but  are  perhaps  preferable  to  dried  prunes  for  home  use.  Select 
well  colored  ripe  prunes  of  large  size.  Wash  and  place  in  cans.  Add 
Medium  syrup  (40  per  cent)  hot.    See  table  1  for  sterilization. 

Cherries — Cherries  canned  without  pitting  develop  a  ''bitter 
almond"  or  "pit"  flavor,  pleasing  to  some  and  disagreeable  to  others. 
Small  hand-pitting  machines  can  be  obtained  from  any  hardware  store 
for  a  small  price.  (See  fig.  8.)  All  pitting  machines  remove  the  pits 
by  means  of  a  cross-shaped  plunger  which  laterates  the  flesh  more  or 
less,  and,  therefore,  the  fruit  must  be  canned  immediately  after  pitting 
to  check  deterioration.  The  Royal  Anne,  a  large  white  cherry,  is 
seldom  pitted.  Cherries  tend  to  shrivel  in  heavy  syrups  or  if  covered 
with  hot  syrups.  Only  moderately  sweet  syrups  should  be  used,  there- 
fore, and  the  cans  exhausted  by  heating  in  boiling  water  or  steam  for  5 
minutes  before  sealing,  rather  than  exhausted  after  adding  hot  syrup. 
See  table  1. 

Blackberries. — Blackberries  shrink  during  cooking  and  the  fruit 
which  fills  a  can  when  fresh  will  shrink  to  about  two-thirds  or  less 


Fia-. 


'. —  Funnel  for  filling  fruit 
and  syrup  into  jars. 


22 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


after  sterilizing.     If  the  cans  are  to  be  well  filled,  the  blackberries 
must  first  be  cooked. 

To  each  pound  of  fruit  add  one  pound  or  less  of  sugar,  according 
to  the  ripeness  of  the  fruit.  Boil  with  gentle  stirring  for  about  3  to 
4  minutes.  Pack  into  cans  or  jars  scalding  hot.  Seal  cans.  Sterilize 
cans  at  the  boiling  point  for  5  minutes.  Lacquered  cans  or  glass  jars 
must  be  used  for  all  berries,  because  plain  tin  bleaches  the  color  of 
the  fruit.  The  extra  syrup  formed  by  the  juice  of  the  fruit  can  be 
used  on  the  next  lot  or  the  excess  moisture  may  be  boiled  off  and  the 
fruit  made  into  a  preserve  before  canning. 


Fig.  8. — Small  hand  x^ower  cherry  pitting  machine  for  home  use. 


An  alternative  method  is  to  cook  with  sugar,  as  directed,  and 
store  over  night.    Heat  to  boiling,  and  proceed  as  above. 

Loganberries. — Loganberries  may  be  canned  by  practically  the 
same  method  as  recommended  for  blackberries.  Lacquered  cans  or 
glass  jars  must  be  used. 

Raspberries. — Raspberries  may  be  canned  as  directed  for  black- 
berries. 

Strawberries. — These  berries  shrink  very  badly  in  volume  if 
cooked  in  the  can.  Therefore,  proceed  as  for  blackberries  after 
hulling. 


(JlKCULAR   276J  HOME   CANNING  23 

Currants,  Cranberries,  Gooseberries. — These  I'm  its  are  used  only 
for  pies,  jellies,  and  jams,  and  are  not  commonly  canned.  They  may 
be  put  up  in  enameled  cans  or  in  jars  in  plain  water  and  sterilized 
at  212°  F.  No  sugar  need  be  used,  although  the  flavor  of  the  fruit 
is  better  if  canned  in  syrup  instead  of  water.    8ee  table  1. 

Grapes. — Muscat  grapes  are  canned  commercially  in  considerable 
quantities  in  California.  The  thoroughly  ripe  grapes  are  removed 
from  the  stems  and  graded  for  size  and  appearance.  Pack  in  cans 
or  jars  and  add  Medium  or  Light  syrup.  The  canned  fruit  is  used 
for  pies.     See  also  table  1. 

Figs. — Figs  are  usually  put  in  glass  in  the  form  of  preserves.  The 
fruit  should  be  allowed  to  ripen  thoroughly  on  the  tree  and  must  be 
handled  carefully  during  picking  and  transferring  to  the  cannery. 

In  commercial  canning,  figs  are  graded,  washed  and  then  blanched 
3  to  4  minutes  in  hot  water.  They  are  then  placed  in  the  cans  in  a 
very  heavy  syrup  (70°  Balling)  and  are  cooked  in  the  sealed  cans 
for  about  two  hours  at  the  boiling  point.  This  method  many  be  used 
in  the  home  also. 

For  home  use,  the  following  method  may  be  used :  Grade  the  figs 
according  to  size.  After  cutting  off  the  stems,  the  fruit  is  weighed 
and  placed  in  a  preserve  kettle.  For  each  pound  of  fruit,  add  1  pound 
of  sugar  and  2  pints  water.  Boil  down  sloAvly  until  the  hot  syrup 
will  test  about  55-60°  Balling  or  33°  Baume,  or  until  the  mixture 
reaches  a  boiling  point  8°  above  the  boiling  point  of  water,  which  is 
for  most  localities  220°  F.,  or  until  the  fruit  is  well  cooked  and  of  a 
consistency  of  a  heavy  preserve.  Jars,  with  their  caps  and  rubbers, 
are  scalded  by  heating  in  boiling  water.  They  are  then  filled  with  the 
boiling  hot  preserve  and  the  caps  screwed  down  loosely.  As  soon  as 
filled  the  jars  should  be  placed  in  hot  water  and  sterilized  at  the 
boiling  point  for  25  to  30  minutes.  Figs  may  be  put  up  in  cans  in 
a  similar  manner.  The  Kadota,  White  Endich  and  other  figs  with 
few  seeds  and  thick  flesh  are  best  suited  to  preserving,  although  the 
Mission,  Calimyrna  and  White  Adriatic  may  be  used. 

Rhubarb. — From  a  culinary  point  of  view,  rhubarb  is  a  fruit  and 
is  very  easily  sterilized  and  canned  in  the  same  general  w^ay  as  fruits. 
Since  it  is  used  chiefly  as  a  pie  stock  no  sugar  need  be  used. 

Wash  the  stalks;  cut  into  short  lengths  and  place  in  a  stewpan, 
with  a  little  water.  Boil  until  soft.  Pack  boiling  hot  into  cans  or 
jars  and  seal.    See  table  1  for  sterilizing. 

Tin  cans  are  soon  badly  corroded  by  rhu])arb  and  prefi^'ably  only 
glass  should  be  used. 


24 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


1.  Preparation  of  the  fruit. 
— Wash,  sort  and  prepare 
the  fruit  as  for  cooking.  Ee- 
move  peel,  cores,  and  pits; 
cut  or  slice  as  desired.  Cook 
as  soon  as  possible  after  cut- 
ting. To  prevent  darkening, 
cut  apples  and  pears  should 
1)6  kept  in  water  until 
cooked. 


2.  Heating  and  cooMng 
with  sugar. — Place  the  pre- 
pared fruit  in  a  pot  and 
then  add  dry  sugar,  Y^  to  % 
lb.  per  pound  of  fruit,  or 
with  very  sweet  fruit  none. 
Add  a  little  water  to  firm 
fruits  to  avoid  scorching. 
Add  no  water  to  berries. 
Heat  to  scalding  tempera- 
ture. Do  not  cook  till  soft. 
Peaches,  pears,  cherries, 
grapes,  and  some  other  firm 
fruits  may  be  canned  with- 
out this  preliminary  cook- 
ing. 


3.  Filling  the  jars. — Warm 
the  jars  with  hot  water,  and 
ladle  the  hot  fruit  into  them 
through  a  funnel  until  they 
are  filled  to  within  1^4  inch 
of  the  top.  Avoid  getting 
juice  on  the  outside.  The 
neck  should  be  dry  and  clean. 
Or  pack  uncooked  firm  fruits 
into  jars  cold.  Add  hot 
syrup  and  proceed  as  in 
steps  4-7. 


Fig.  9, — Preparing  fruits  for  modified  hot  pack  process. 


4.  Tlacing  ruhbers  and 
covers. — Test  clean  scalded, 
rubbers  by  bending  and 
stretching.  They  should  not 
crack.  Put  evenly  in  place 
on  the  necks  of  the  jar,  then 
apply  the  covers,  placing  or 
screwing  them  loosely,  and 
lower  the  jars  into  the  ster- 
ilizer, placing  a  piece  of 
wire  screening  or  other  false 
bottom  in  the  bottom  of  the 
boiler. 


5.  isienUzing  in  a  wash 
boiler. — Pour  in  a  few  inches 
of  hot  water  around  the  jars. 
Apply  the  cover  of  the 
boiler.  Unless  the  cover  fits 
very  well  place  a  cloth  be- 
neath it.  Heat  until  steam 
comes  from  beneath  the 
cover  and  then  for  the  time 
specified  in  table  1,  page  36. 


6.  Bemoval  from  the  boiler. 
— Eemove  immediately.  Han- 
dles on  the  wire  screen 
bottom  or  wire  baskets  to 
hold  the  jars  facilitate  re- 
moval. A  cloth  or  a  wire 
jar  lifter  may  be  used.  The 
lifter  in  the  illustration 
serves  well  for  lifting  jars 
and  as  a  false  bottom.  Place 
hot  jars  on  wood  or  paper  to 
avoid   cracking. 


7.  Tightening  the  covers. 
— Tighten  the  covers  imme- 
diately and  stand  the  jars 
upside  down.  This  insures 
the  sterilization  of  the  cov- 
ers. Leaky  jars  can  be  de- 
tected by  air  bubbles  enter- 
ing during  cooling. 


Fig.  10. — Sterilizing  and  sealing  jars  of  fruit. 


26  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

Grape  Fruit  (Pomelo).— Grape  fruit  is  now  canned  in  large  quan- 
tities in  Porto  Rico  and  Florida  and  the  industry  is  well  established 
in  California.  Use  only  thoroughly  ripened  fruit.  Peel.  Separate 
the  segments  and  peel  these.  Pack  the  peeled  segments  into  jars  or 
cans.  Add  a  boiling  hot  syrup  of  50°  Balling.  Grape  fruit  may 
also  be  canned  in  slices  or  cubes.    See  table  1  for  sterilization. 

Jelly  Juices. — Boil  jelly  fruits  as  for  jelly  making.  Thus,  berries 
and  currants  are  crushed,  boiled  5  minutes  and  without  addition  of 
water;  apples  are  sliced  without  previously  peeling;  enough  water 
is  added  to  prevent  scorching  and  the  fruit  is  boiled  until  soft,  usuall}^ 
15-20  minutes.  Press  the  boiled  fruits  and  strain  the  juice.  Heat 
juice  to  boiling;  pack  into  scalded  jars  and  sterilize  as  directed  in 
table  1.    Cans  are  not  recommended  for  jelly  juices. 

Crown  capped  bottles  may  be  used  instead  of  jars  if  desired.  (See 
Circular  220.) 

To  use  the  jelly  juice  at  a  later  date  simply  drain  the  juice  care- 
fully from  the  sediment  in  the  jar — add  the  customary  amount  of 
sugar  and  boil  until  the  jelling  point  is  reached. 

Ripe  Olives. — Two  Lye  Process. — The  Mission  variety  is  best  for 
home  pickling,  although  the  Manzanillo  variety  is  also  fairly  satis- 
factory. The  Sevillano  and  Ascolano  varieties  are  very  difficult  to 
pickle  and  should  not  be  used  by  those  unfamiliar  with  the  pickling 
of  ripe  olives. 

Harvesting. — Pick  the  olives  after  they  have  acquired  a  light  pink 
to  red  color  and,  if  possible,  before  they  have  become  jet  black  and 
over-ripe.  Avoid  bruising  and  prolonged  storage  in  boxes  before 
pickling. 

Holding  Solution. — If  for  any  reason,  it  is  necessary  to  ship  the 
olives  a  great  distance  or  to  store  them  for  a  week  or  longer  before 
pickling,  cover  them  in  suitable  containers  with  a  5  per  cent  salt 
solution  (about  4  pounds  of  salt  per  10  gallons)  for  three  or  four 
days.  Then  cover  them  with  a  brine  of  about  12  per  cent  salt  (about 
9  pounds  salt  per  10  gallons  of  water)  and  keep  the  olives  submerged 
in  this  solution  until  used.  However,  in  home  canning  the  olives  will 
usually  be  pickled  direct  from  the  tree. 

First  Lye. — Prepare  a  lye  solution  of  about  I14  to  II/2  per  cent; 
this  is  approximately  II/2  to  2  ounces  of  granulated  lye  per  gallon  of 
water,  or  approximately  I/2  to  %  pound  per  5  gallons  of  water.  If 
the  olives  are  tender  use  not  more  than  1  ounce  of  lye  per  gallon  of 
water. 


Circular  276]  HOME  CANNING  27 

Cover  the  olives  in  a  stoneware  jar  or  wooden  container  with  this 
lye  solution.  Stir  every  half  hour  and  carefully  observe  the  progress 
of  the  lye.  The  color  of  the  skins  will  change  as  the  lye  penetrates  the 
olives.  Cut  two  or  three  olives  lengthwise  occasionally  and  when  it  is 
observed  that  the  lye  has  penetrated  through  the  skins  of  practically 
all  of  the  olives  and  a  short  distance  (%4-%2  inch)  into  the  flesh  of 
some  of  them,  remove  and  discard  the  lye  solution.  With  lye  at 
60-65°  F.  the  time  required  is  usually  four  to  six  hours.  With  tender 
skinned  olives  or  at  higher  temperatures  less  time  and  with  tough 
skinned  olives  and  lower  temperatures  more  time  may  be  required. 

First  Exposure  to  Air. — Leave  the  olives  in  the  jar  or  tub  and  stir 
three  times  daily  to  facilitate  darkening  of  the  color  by  oxidation. 
In  order  to  avoid  bruising,  large  tubs  of  olives  may  be  filled  with 
water  at  the  time  of  stirring  and  the  water  draAvn  off  after  stirring. 
In  small  containers  the  fruit  may  be  stirred  with  the  hands  without 
adding  water. 

Normally  four  to  five  days'  exposure  to  air  is  required  to  give  the 
desired  color. 

Second  Lye. — The  first  lye  treatment  is  to  facilitate  darkening  of 
the  color.    The  second  is  to  remove  bitterness. 

Prepare  a  solution  of  one  ounce  of  lye  per  gallon  of  water  and 
place  it  on  the  olives.     Stir  them  occasionally  (about  once  an  hour). 

Cut  two  or  three  olives  occasionally  and  carefully  observe  the 
lye  action ;  it  causes  the  flesh  to  darken  slightly  in  color.  Or  obtain 
from  the  druggist  a  small  bottle  of  Plienolplitlialein  solution.  A  drop 
of  this  solution  applied  to  the  cut  surface  will  develop  a  red  color 
to  the  depth  of  the  lye  penetration.  If  this  solution  is  used,  rinse  the 
lye  from  the  olive  in  water  before  cutting  it  for  the  test. 

Leave  olives  in  the  lye  solution  until  it  completely  reaches  the 
pits  of  the  fruit  (usually  8-16  hours  at  60-65°  F.). 

Water  Treatment  to  Remove  Lye. — When  the  lye  has  reached  the 
pits  of  the  olives  remove  and  discard  it.  Cover  the  olives  with  water 
and  leave  them  submerged  in  the  water. 

Change  the  water  three  times  daily  until  all  taste  of  lye  is  removed 
or  until  the  cut  surface  will  no  longer  cause  the  test  solution 
(Phenolphthalein)  to  turn  red  or  pink.  Normally,  seven  days  soaking 
in  water  is  required. 

Curing  in  Brine. — The  olives  at  this  stage  are  edible,  but  require 
salt  to  ''bring  out"  their  flavor.  Store  the  olives  for  three  days  in 
a  brine  of  about  4  ounces  (^/4  pound)  of  salt  per  gallon  of  water. 
They  are  then  ready  for  serving  or  canning. 


28  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Canning  and  Sterilizing. — Pack  into  cans  or  jars.  Add  boiling 
hot  brine  of  4  ounces  (i/4  pound)  of  salt  per  gallon.  Seal  cans.  Place 
scalded  rubbers  and  caps  on  jars. 

Sterilize  as  directed  for  vegetables  in  a  pressure  cooker  at  240°  F. 
for  40  minutes  (10  pounds  steam  pressure). 

THE  STATE  BOAPvD  OF  HEALTH  Hx\S  RULED  THAT  ALL 
OLIVES  OFFERED  FOR  SALE  MUST  BE  STERILIZED  IN 
THIS  MANNER. 

One  Lye  Process. — The  preceding  process  produces  olives  of  dark 
color.  If  this  color  is  not  desired  a  lighter  colored  product  of  superior 
flavor  may  be  prepared  by  a  single  treatment. 

In  using  this  process  cover  the  olives  with  a  lye  solution  of  2  per 
cent  (2^/^  ounces  of  lye  per  gallon  of  water)  and  allow  it  to  stand 
with  occasional  stirring  until  the  lye  penetrates  completely  to  the  pit ; 
normally  12  to  24  hours. 

Remove  the  lye.  Cover  the  olives  with  water.  Change  the  water 
three  times  daily  until  all  taste  of  lye  is  removed  (6-7  days). 

Cure  in  brine,  can  and  sterilize  as  directed  for  the  two  lye  process. 


D.  SPECIAL  DIRECTIONS  FOR  VEGETABLES 

Most  vegetables  have  only  a  small  amount  of  acid  as  compared 
with  fruits.  This  low-  degree  of  acidity,  as  we  have  seen,  permits  the 
growth  of  certain  bacteria  which  are  very  difficult  to  kill  by  heating. 
Vegetables,  therefore,  are  hard  to  sterilize.  Tomatoes,  which  resemble 
fruit  in  respect  to  their  acidity,  are  an  exception. 

Usually  in  sterilizing  vegetables  temperatures  above  212°  F.  are 
necessary.  This  requires  the  use  of  tin  cans  and  a  steam-pressure 
cooker.  Steam-pressure  cookers  are  not  difficult  to  operate  and  can 
be  obtained  at  prices  as  low  as  $18.00. 

Note. — Where  a  pressure  sterilizer  is  not  available,  it  is  advised 
that  vegetables  be  dehydrated.  A  leaflet  describing  the  construction 
and  operation  of  an  inexpensive  home  size  dehydrater  for  fruits  and 
vegetables  is  obtainable  free  of  charge  from  the  College  of  Agricul- 
ture, Berkeley. 

Artichokes. — Young  artichokes  only  are  used.  The  hard  tip  is 
trimmed  off  and  some  of  the  outer  bracts  removed,  leaving  only  the 
tender  parts. 

They  are  blanched  for  5  minutes  in  boiling  water,  acidified  with 
%  measuring  cup  of  lemon  juice  or  vinegar  per  gallon,  placed  in 
cans  or  jars  and  covered  with  hot  2  per  cent  brine.  For  sterilization 
see  table  2. 


Circular  276] 


HOME    CANNING 


29 


Asparagus. — Grade  into  larg-e,  iiiediiiin,  and  small  sizes.  Cut  into 
lengths  to  fit  the  container.  This  is  conveniently  done  by  making  a 
small  box,  i/4  ^^^ch  less  than  the  depth  of  the  can  or  jar  and  open  at 
the  top  and  one  side.  The  bud  ends  of  the  stalks  are  placed  in  the 
box  against  the  closed  end  and  the  butts  protrude  from  the  open  end. 
They  ma}^  be  cut  off  flush  with  the  edges  of  the  open  side  of  the  box 
with  a  large  sharp  knife. 

Blanch  the  stalks  in  boiling  water  for  about  4  minutes.  Pack  into 
jars  or  cans  with  the  tips  up.  Fill  with  hot  brine  and  seal.  Sterilize 
as  directed  in  table  2. 


Fig.  11. — Pressure  sterilizer  for  home  une.     (Courtesy  of  the  Heuuinger  Ayes  Co.) 

Green  Beans. — Green  beans  are  best  for  canning  when  very  young 
and  tender,  the  larger  and  harder  the  pods  and  beans  become,  the 
lower  their  value  for  canning.  Commercially,  beans  are  usually  put 
up  in  No.  2  cans. 

Snip  or  string  after  sorting.  The  larger  sizes  should  be  cut  into 
pieces  about  one  and  one-half  inches  long,  while  the  small  or  No.  1 
grade  may  be  canned  whole. 


30  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Blanch  the  No.  1  grade  two  minutes  in  boiling  water  and  the  larger 
grades  for  five  minutes.    Fill  into  cans  hot. 

Fill  with  hot  brine  and  seal  cans.    Sterilize  as  directed  in  table  2. 

Beets. — Beets  should  be  small  and  turnip-shaped  if  canned  for 
market.  The  first  grade  may  be  1  to  l^/o  inches  in  diameter  and  the 
second  over  one  and  one-half  inches.  The  large  beets  are  quartered 
after  peeling. 

Scald  in  boiling  water  or  in  steam  until  the  skin  will  slip  easily, 
usually  about  fifteen  minutes.  Chill  in  cold  water,  peel,  trim,  and  fill 
into  enamel  lined  cans.  Fill  with  hot  brine  and  seal.  Sterilize  as 
directed  in  table  2. 

Sweet  Corn. — Only  young  tender  ears  of  good  varieties  of  sugar 
corn  should  be  used.  The  corn  must  be  fresh  if  good  results  are  to 
be  expected.  The  ears  are  husked,  and  the  corn  is  cut  from  the  cob. 
A  syrup  of  %  pound  (one  measuring  cup)  of  sugar  and  II/2  ounces 
salt  (4  level  tablespoons)  per  gallon  is  made.  The  corn  and  a  small 
amount  of  syrup  (enough  to  cover  the  corn)  are  mixed  and  heated 
in  a  pot  to  boiling.  The  mixture  is  filled  hot  into  cans,  sealed  and 
sterilized  as  directed  in  table  2.    Cool  the  cans  after  sterilizing. 

Peas. — Picking  and  hulling  peas  by  hand  is  a  very  slow  process  and 
not  to  be  recommended  for  commercial  canning.  Large  canneries 
do  the  hulling,  grading,  blanching,  and  filling  of  cans  entirely  by 
machinery.  It  is  feasible,  however,  to  shell  enough  peas  for  canning 
by  hand  for  home  use.    Use  only  fresh,  tender  peas. 

Place  the  shelled  peas  in  a  wire  basket  or  in  a  clean  cloth  and 
blanch  in  boiling  water  long  enough  to  wringle  the  skin  slightly.  This 
will  usually  be  about  one  to  four  minutes,  depending  upon  the  size 
and  tenderness  of  the  peas. 

Fill  into  cans  and  fill  with  hot  brine,  consisting  of  2  ounces  (5 
tablespoons)  of  salt  and  I/2  measuring  cup  of  sugar  per  gallon  and 
seal  cans.    Sterilize  as  directed  in  table  2. 

Peppers,  Pimientos. — These  vegetables  are  usually  peeled  by  caus- 
ing the  skin  to  separate  by  roasting  or  by  immersing  in  hot  oil.  They 
can  be  peeled  successfully  by  im^mersing  from  two  to  three  minutes 
in  cottonseed  oil  heated  to  smoking.  They  are  then  chilled  at  once 
in  cold  water  and  the  skins  come  off  easily  from  the  large  peppers  and 
pimientos.  Small,  pungent,  tough-skinned  Mexican  peppers  do  not 
yield  so  well  to  this  treament.  When  peeled  in  this  w^ay,  the  peppers 
are  obtained  soft  and  pliable  and  can  be  folded  into  the  cans  after 
removing  stems  and  seed  cores.  The  peppers  or  pimientos  may  also 
be  peeled  by  roasting  in  a  gas  flame  or  in  a  very  hot  oven  until  the 
skin  will  separate. 


Circular  276]  HOME  CANNING  31 

Pack  the  peeled  product  into  cans.  Fill  with  ])oilin<?  water  or 
brine.    Sterilize  as  directed  in  table  2. 

Pumpkin. — Scrape  out  fibrous  pulp  and  seeds  and  cut  the  flesh 
and  rind  into  strips.  Boil  in  water  until  soft.  Scrape  the  flesh  from 
the  rind  and  press  through  a  colander.  Boil  to  desired  consistency. 
Pack  hot  into  cans  and  seal.    Sterilize  as  directed  in  table  2. 

Tomatoes. — Tomatoes  have  a  considerable  amount  of  acid  wliich 
checks  the  growth  of  heat-resistant  bacteria.  They  are,  therefore, 
easily  sterilized  at  212°  F.  and  jars  may  be  used  satisfactorily. 

For  canning  purposes,  the  variety  used  should  be  smooth  and  of 
a  deep  red  color.  Corrugated  tomatoes  are  too  difficult  to  peel.  The 
Stone  is  an  excellent  canning  variety. 

Sort  the  tomatoes  and  reject  those  which  are  spoiled  and  under- 
ripe. Place  them  in  a  blanching  basket  and  immerse  in  boiling  water 
long  enough  to  crack  and  loosen  the  skin.  This  will  usually  be  about 
one-half  to  one  minute.  Remove  and  chill  in  cold  water.  Slip  off  the 
skins  and  remove  the  cores.  Pack  the  tomatoes  tightly  into  jars  or 
cans  and  fill  with  juice  or  heat  to  boiling  in  the  juice  obtained  in  coring 
and  pack  tightly  into  c^ns  or  jars  hot  and  seal.  If  packed  cold  in 
cans,  the  filled  cans  should  be  heated  in  boiling  water  or  live  steam 
for  five  minutes  before  sealing.     Sterilize  as  dire<?ted  in  table  1. 

If  the  tomatoes  are  packed  without  the  addition  of  juice,  the 
product  is  known  as  ''solid  pack;"  if  juice  is  added,  as  "standard 
pack." 

Tomatoes  may  be  canned  whole  to  be  used  for  slicing  for  salads, 
although  they  will  soften  somewhat.  Select  small  tomatoes  that  will 
go  into  the  jars  or  cans.  Cover  with  a  hot  tomato  juice  pressed  from 
crushed  fresh  tomatoes.     Seal.     Sterilize  as  directed  in  table  1. 

Tomato  Puree  and  Hot  Sauce. — Tomato  puree  or  sauce  is  very  con- 
venient for  flavoring  many  dishes,  such  as  stews,  soups  and  macaroni. 
Cook  until  soft.  Rub  through  a  fine  screen  to  remove  skins,  seeds, 
and  fiber.  Concentrate  the  puree  to  about  one-half  its  original  volume 
by  boiling.  Pack  boiling  hot  into  cans  or  jars  and  seal  cans.  Sterilize 
as  directed  in  table  1.  If  a  hot  sauce  is  desired,  add  salt,  chopped 
onions,  and  hot  peppers  to  taste  to  the  tomatoes  before  cooking  and 
screening. 

Sweet  Potatoes.— Wash.  Boil  until  the  skins  will  slip  easily.  Peel 
quickly  and  pack  hot,  filling  the  cans  as  tightly  as  possible.  Seal. 
Sterilize  as  directed  in  table  2.  After  removal  from  sterilizer  cans 
should  be  chilled  at  once  in  cold  water. 


32  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Spinach  and  Other  Greens. — Can  as  soon  after  picking  as  possible. 
Trim  off  stems  and  imperfect  portions.  Wash  thoroughly  to  remove 
sand,  etc.  Blanch  3  to  5  minutes  in  steam  rather  than  in  water. 
Water  dissolves  valuable  food  material.  Pack  hot  into  cans.  Fill 
with  hot  brine  and  seal.    Sterilize  as  directed  in.  table  2. 

Okra  (Gumbo). — This  vegetable  is  grown  frequently  in  the  hot 
sections  of  the  state  for  flavoring  soups,  stews,  and  other  dishes.  The 
pods  resemble  green  peppers  in  appearance. 

Use  only  the  young,  tender  pods  for  canning.  Remove  stems. 
Blanch  6  to  8  minutes  in  boiling  water.  Pack  into  cans  with  boiling 
water.     Sterilize  as  directed  in  table  2. 

Concentrated  Soup  Mixtures. — Vegetables  such  as  carrots,  onions, 
tomatoes,  beans,  etc.,  may  be  prepared  as  for  vegetable  soup  and 
canned.  A  recipe  recommended  by  the  United  States  Department 
of  Agriculture  is  as  follows: 

''A  good  combination  consists  of  1  quart  of  screened  concentrated 
tomato  pulp  (boiled  tomatoes  screened  and  two  volumes  of  pulp  boiled 
down  to  one  volume),  1  pint  of  green  corn  or  tiny  Lima  beans,  1  pint 
of  okra  or  sweet  peppers,  1  small  onion  chopped,  %  cup  of  chopped 
sweet  red  pepper,  II/2  teaspoonfuls  of  salt,  and  3  teaspoonfuls  of 
sugar.  Cook  the  tomatoes,  pepper,  and  onion;  put  through  a  sieve 
to  remove  seeds ;  and  cook  down  to  about  the  consistency  of  ketchup. 
Measure,  add  the  corn  or  beans  and  okra,  which  have  been  prepared 
as  for  canning.  Add  the  seasoning  and  cook  all  together  for  10  min- 
utes. Pack  at  once  into  hot  jars,  and  process  as  directed  in  table  2. 
Tin  cans  should  be  plunged  immediately  into  cold  water  and  cooled 
as  quickly  as  possible.    When  cool,  store  in  a  dark,  dry,  cool  place." 

If  all  of  the  vegetables  recommended  are  not  available,  others  may 
be  substituted,  thus,  cooked  white  beans  for  corn,  pimientos  for  okra, 
white  potatoes  for  Lima  beans.  Celery  makes  a  valuable  addition  to 
the  mixture.  When  used  for  soup  the  canned  product  is  diluted  with 
water  and  flavored  with  bouillon  cubes  or  meat  broth.  For  con- 
venience it  should  be  put  up  in  small  cans. 


E.     SPECIAL  DIRECTIONS  FOR  MEATS 

Meats,  owing  to  their  texture  and  absence  of  acidity  are  even  more 
difficult  to  sterilize  than  vegetables.  If  incompletely  sterilized,  they 
may  be  attacked  by  certain  heat-resistant  bacteria  which  produce 
dangerous  poisons.  By  carefully  carrying  out  the  directions  given 
in  this  circular,  however,  there  is  no  danger  from  this  source. 


Circular  270]  HOME  CANNING  33 

For  home  canning,  the  meat  should  first  be  seasoned  and  partially 
cooked.  For  example,  chicken  or  rabbit  may  be  fried  a  short  time 
before  being  placed  in  the  cans  and  beef  should  be  corned  or  cooked 
in  some  suitable  way  before  canning. 

The  meat  should  be  placed  in  the  containers  as  hot  as  possible,  as 
heat  penetrates  slowly  during  sterilization.  The  spaces  between  the 
pieces  of  meat  should  be  filled  with  hot  liquid,  such  as  a  suitable  sauce. 
A  hot,  dilute  gelatin  solution  is  suitable,  as  it  forms  a  stiff  jelly  be- 
tween the  pieces  of  meat.  Any  good  brand  of  unflavored  gelatine 
will  do. 

After  filling  and  before  sealing  and  sterilizing,  cans  should  be 
exhausted  in  boiling  water  for  10  to  20  minutes  before  sealing.  Jars 
should  not  be  used. 

Meat  requires  40  to  80  minutes  at  15  pounds  steam  pressure. 

Canned  Boiled  Beef. — Remove  the  bones  and  rub  the  pieces  of 
meat  with  a  mixture  of  5  parts  of  salt  and  1  part  of  sugar.  To  im- 
prove the  color  a  very  small  amount  of  saltpetre  may  be  mixed  with 
the  salt.  Repeat  this  rubbing  12  hours  later.  Tie  the  pieces  together 
with  twine  and  place  in  a  pot,  covering  with  salted  water.  Simmer 
for  about  two  hours  or  until  the  meat  is  tender.  Cooking  before  can- 
ning is  necessary  to  prevent  shrinkage  in  volume  in  the  can.  The 
flavor  may  be  improved  by  placing  a  cotton  bag  containing  a  small 
quantity  of  mixed  spices  in  the  liquid  while  cooking.  A  suitable 
mixture  is  black  pepper,  24  parts ;  bay  leaves,  8  parts ;  mace,  6  parts ; 
and  nutmeg,  3  parts.    A  little  vinegar  may  also  be  added. 

When  cooked,  cut  the  meat  into  pieces  of  suitable  size  and  fill  the 
cans  and  cover  with  hot  meat  bouillon.  This  bouillon  is  made  by  boil- 
ing down  the  liquor  in  which  the  meat  was  cooked  and  adding  a  little 
gelatine  previously  dissolved  in  water.  Seal  cans  and  sterilize  as 
directed  in  table  2. 

Chicken  and  Rabbit.— Boil  in  lightly  salted  water  until  tender  and 
remove  the  bones.  Pass  through  a  meat  chopper  if  desired.  Mix  the 
prepared  meat  with  a  highly  seasoned  tomato  sauce  or  with  a  white 
sauce  made  of  flour,  water,  and  spice;  or  other  suitable  sauce,  and 
pack  in  cans  or  jars.  Several  ripe  olives  added  to  each  can  is  an 
improvement. 

Heat  cans  for  20  minutes  in  boiling  water,  seal,  and  sterilize  as 
directed  in  table  2. 

The  meat  may  also  be  canned  with  the  bones.  It  may  be  fried, 
roasted,  or  boiled,  cut  into  pieces  of  suitable  size,  and  packed  in  cans 
or  jars  in  the  liquid  in  which  it  is  cooked,  and  sterilized  as  above. 


34  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

It  may  also  be  placed  in  the  cans  raw  and  cooked  and  sterilized 
at  the  same  time,  but  when  prepared  in  this  way,  is  inferior  in  flavor 
and  appearance  and  shrinks  greatly  in  volume. 

Fish. — Small  fish  may  be  canned  whole;  large  fish  are  cut  into 
pieces  of  convenient  size.  Cooking  and  sterilizing  take  place  in  the 
can. 

Large  Fish. — After  cleaning  and  cutting  into  pieces,  the  fish  is 
improved  if  sprinkled  with  salt  and  allowed  to  stand  and  drain  for 
a  few  hours.  It  is  then  washed,  packed  in  cans,  and  covered  with 
brine.  It  is  then  heated  in  the  open  cans  in  boiling  water  or  steam 
for  twenty  minutes  and  the  cans  are  sealed. 

Small  Fish. — The  principal  small  fish  canned  is  the  sardine,  though 
other  small  fish,  such  as  small  trout,  may  be  canned  in  a  similar  way. 

They  may  be  canned  in  a  tomato  catsup  or  a  mustard  and  vinegar 
sauce,  flavored  with  spices.  The  heads  of  the  fish  are  cut  off,  the  scales 
removed  if  necessary,  and  the  fish  cleaned.  They  are  then  cooked  in 
boiling  water  or  steam,  drained,  and  packed  in  cans.  The  hot  sauce 
is  then  poured  over  them  and  the  cans  sealed  and  sterilized. 

They  may  also  be  canned  in  olive,  cottonseed,  or  peanut  oil.  They 
are,  in  this  case,  prepared  as  above,  but  are  cooked  in  boiling  oil 
instead  of  steam.  They  are  then  packed  in  cans  with  the  oil,  sealed 
and  sterilized.  Fish  may  be  kippered  before  canning  by  smoking  for 
two  to  three  hours  in  smoke  from  oak  sawdust.  If  to  be  kippered,  the 
fish  should  be  stored  in  brine  (about  1/2  pound  of  salt  per  gallon)  for 
3-4  hours  before  smoking. 

With  tomato  or  vinegar  sauces,  heating  for  40  minutes  at  240°  P. 
is  sufficient  for  sterilization.  In  oil  or  a  sauce  that  is  not  acid,  they 
require  heating  to  250°  F.  or  15  pounds  pressure  for  75  minutes. 


F.     PTOMAIN  AND  BOTULINUS  POISONING 

If  meat  or  vegetables  are  found  after  canning  and  storage  to  be 
partially  decomposed  or  ''soured,"  they  may  contain  dangerous 
poisons. 

Ptomains. — Poisonous  ptomains  rarely  occur  in  canned  food. 
They  are  produced  by  forms  of  protein-destroying  bacteria,  for 
example,  by  Bacillus  protend  vidgaris,  one  of  the  commonest  organisms 
of  spoiled  meat.  The  presence  of  ptomains  is  usually  accompanied  by 
a  noticeable  odor  of  decomposition.  So  far  as  is  known,  they  do  not 
frequently  occur  in  cannc^l  fruits  or  vegetables.  Ptomains  are  not 
destroyed  by  heating,  so  that  badly  spoiled  meat  is  not  rendered 
harmless  b}^  canning  or  cooking. 


ClHCULAH    276J  HOME    (!ANNIN(;  '55 

Hokdinus  Poisoning. — A  more  violent  poison  is  produced  hy 
Bacillus  hohdinns,  a  microorganism  which  may  grow  in  meats,  vege- 
tables and  fruits  low  in  acid.  This  bacteria  sometimes  grows  in  cans 
and  jars  of  vegetables  put  up  by  the  ordinary  household  method  in 
which  the  food  is  not  sterilized  in  the  jar,  and  deaths  have  occurred 
froni  the  use  of  such  canned  vegetables  in  the  uncooked  state.  It  is 
very  dangerous  to  can  such  vegetables  as  peas,  beans,  or  corn,  simply 
by  cooking  them  until  they  are  done  and  then  sealing  them  in  cans  or 
jars  without  further  sterilization.  The  heat  in  this  method  is  not 
sufficient  to  kill  the  spores  of  the  Bacillus  botulinus  which  may  develop 
later  and  produce  enough  poison  to  be  fatal. 

The  botulinus  toxin  is  many  times  more  poisonous  than  strychnine 
and  is  very  hard  to  detect ;  the  only  outward  evidence  of  its  presence 
being  a  more  or  less  rancid  odor  and  gas  pressure.  The  poison  is,  how- 
ever, destroyed  by  heating  to  the  boiling  point  for  a  reasonably  long 
period  (30  minutse).  Therefore,  if  canned  vegetables  are  thoroughly 
cooked  after  opening,  there  is  little  danger  of  botulinus  poisoning. 

The  botulinus  bacteria  will  not  grow  readily  in  acid  substances, 
such  as  most  fruits,  rhubarb  and  tomatoes.  The  organism,  however, 
may  grow  in  rare  cases  in  fruits  of  low  acidity,  such  as  pears  and 
over-ripe  apricots,  etc. 

Never  Taste  Spoiled  Canned  Food. — Suspicious  jars  or  cans  of 
food,  that  is,  those  which  possess  a  disagreeable  odor  or  show  gas 
pressure,  should  be  destroyed  without  tasting.  The  contents  of  such 
jars  should  be  mixed  with  several  spoonfuls  of  lye  and  jar  and  con- 
tents buried.  Suspected  material  should  be  destroyed  and  not  fed 
to  chickens  or  animals.  Many  cases  are  on  record  in  which  valuable 
chickens  have  been  killed  by  eating  spoiled  canned  foods.  Other  cases 
of  fatal  poisoning  have  resulted  from  merely  tasting  spoiled  cans  of 
food. 

If  the  methods  recommended  in  this  circular  are  carefully  followed 
there  will  be  no  danger  from  botulinus  poisoning. 

Pressure  Sterilization  of  Vegetables  Necessary. — Vegetables,  except 
rhubarb  and  tomatoes,  must  be  sterilized  under  steam  pressure  as 
directed  in  table  2  in  order  to  be  safe.  Do  not  attempt  to  sterilize 
such  vegetables  in  boiling  water  or  an  open  steam  cooker  only.  This 
circular  supersedes  Circular  No.  158  and  other  publications  in  which 
sterilizing  in  boiling  water  may  be  fou7id  recommended.  Disregard 
the  direction.'^  in  these  older  publications. 


36 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


G.  CONDENSED  DIRECTIONS 

Tables  1   and  2  give  brief   directions  for  preparation   and  safe 
periods  of  sterilization  for  home  canned  products. 


TABLE  1 


Variety 


Apples 

Apricots 

Berries,  all  varieties. 

Cherries,  sweet 


Cherries,  sour  for  pie. 
Figs  (preserved) 


Figs  in  syrup 

Grapes,  Muscat. 

Peaches,  cling 


Peaches,  free. 
Pears 


Plums. 


Prunes,  fresh. 
Rhubarb 


Tomatoes 

Tomato  puree. 
Jelly  jviiees 


Fruit  juices. 


Preparation 


Peel,  core,  quarter,  blanch 

3-4  min. 
Halve  and  pit;  blanch  in 

medium  syrup  3-4  min. 
Boil   3   min.    with   equal 

weight  of  sugar,  stand 

24  hours,  pack  hot. 
Stem;  pit  if  desired 


Stem  and  pit 

Equal  parts  sugar,  fruit, 
and  water  cooked  to 
preserves;  can  hot. 

Sort  and  wash 

Stem 


Halves,  pit  and  peel. 


Halves,  pit  and  peel.. 
Peel,  halve,  and  core.. 

Sort,  stem,  and  wash. 


Halves,  pit  and  peel 

Wash,  cut,  and  stew  un- 
til soft;  pack  hot;  no 
sugar. 

Scald,  cold,  dip,  peel,  and 
core. 

Boil  soft,  screen,  boil  to 
Yi  volume  and  can  hot. 

Boil  fruit;  press  and  strain 
juice  as  for  jelly  mak- 
ing; can  hot. 

(See  Circular  220) 


Syrup  *  recommended 


Water. 


Medium  or  heavy;  40  or 

60°  Bal. 
In  own  syrup 


Medium  or  light;  40  or  20° 


Water 

In  own  syrup. 


Very  heavy;  70-75°  Bal... 
Medium  or  light;   40  or 

20°  Bal. 
Medium  or  heavy;  40  or 

60°  Bal. 

do 

Medium  or  light;   40   or 

20°  Bal. 
Heavy  or  medium;  00  or 

40°  Bal. 

Medium;  40°  Bal 

In  own  juice 


In  own  juice.. 
In  own  juice.. 
In  own  juice.. 


Minutes  steriliza- 
tion in  boiling 
water  or  steam 
at  212°  F. 


Quart 
jars 


120 
20 


35 


20 


Quart 
cans 


120 
15 


30 


10 


*  Syrups:  For  convenienC3,  syrups  are  classified  as:   Light,  1  cup  of  sugar  to  4 
1  cup  of  sugar  to  2  of  water,  and  heavy,  1 14,  cups  of  sugar  to  1  of  water. 


of  water;  Medium, 


Circular  276] 


HOME   CANNING 


37 


TABLE  2 

Condensed  Directions  for  Vegetables,  Olives,  and  Meats 

For  brines  see  special  directions  for  each  product.     Use  only  cans  for  products 
listed  in  this  table. 


Variety 

Preparation 

Minutes  sterilization 

At  10  lbs. 
pressure 

At  15  lbs. 
pressure 

Blanch  5  minutes  in  water  with  %  cup  vinegar 
per  gal. 

30 

30 
30 
30 
150 
65 
40 
40 
50 

120 

90 

50 

120 

20 

20 

String  beans 

Snip,  cut,  and  blanch  2-10  minutes 

Beets 

80 

Greens  and  spinach 

Trim,  wash,  blanch  5  minutes 

60 

Okra  ("gumbo") 

Cut;  blanch  6—8  minutes 

Pimientos  and  peppers... 

Pumpkin  and  squash 

Sweet  potatoes 

Roast  in  flame  or  oven  or  heat  in  hot  oil;  chill;  . 

peel  and  core. 
Cut;  remove  seeds  and  "rag";  cook;  scrape  from 

skin;  pack  without  brine. 
Cook;  peel;  pack  solid  without  brine 

90 
75 

Vegetable  soup  mixture.. 
Meats  and  fish 

Cook,  pack  in  Uquid  from  cooking,  heat  in  steam 
20  minutes;  seal. 

75 

Effect  of  Altitude. — The  times  given  in  Table  1  for  sterilizing  in 
boiling  water  are  designed  for  altitudes  from  sea  level  to  1,000  feet* 
For  altitudes  above  1,000  feet  the  length  of  sterilization  in  boiling 
water  should  be  increased  about  20  per  cent  (one-fifth)  for  each  addi- 
tional one  thousand  feet.  Thus  at  2,000  feet  a  sterilizing  time  of  60 
minutes  in  boiling  water  would  become  60  plus  12,  or  72  minutes. 

Sterilization  under  pressure  is  also  affected  by  altitude ;  therefore, 
the  pressure  should  be  increased  1  pound  for  each  2,000  feet  increase 
in  elevation.  The  pressures  and  times  in  the  table  apply  from  sea  level 
to  about  2,000  feet. 


STATION  PUBLICATIONS  AVAILABLE  FOR  FREE  DISTRIBUTION 


BULLETINS 


No. 
253. 

261. 

262. 

268. 
268. 
273. 

275. 

276. 
277. 
278. 
279. 
280. 

283. 
285. 
286. 
287. 
294. 
298. 
804. 

312. 
317. 

319. 
321. 
324. 

325. 


828. 
331. 
384. 

335. 

336. 

339. 

343. 
344. 


Irrigation  and  Soil  Conditions  in  the 
Sierra  Nevada  Foothills,  California. 

Melaxuma  of  the  Walnut,  "Juglans 
regia." 

Citrus  Diseases  of  Florida  and  Cuba 
Compared  with  those  of  California. 

Size  Grades  for  Ripe  Olives. 

Growing  and  Grafting  Olive  Seedlings. 

Preliminary  Report  on  Kearney  Vine- 
yard Experimental  Drain. 

The  Cultivation  of  Belladonna  in  Cali- 
fornia. 

The   Pomegranate. 

Sudan  Grass. 

Grain   Sorghums. 

Irrigation  of  Rice  in  California. 

Irrigation  of  Alfalfa  in  the  Sacramento 
Valley. 

The  Olive  Insects  of  California. 

The  Milk  Goat  in  California. 

Commercial   Fertilizers. 

Vinegrar  from  Waste  Fruits. 

Bean   Culture  in   California. 

Seedless  Raisin  Grapes. 

A  Study  of  the  Eflfects  of  Freezes  on 
Citrus   in   California. 

Mariout  Barley. 

Selections  of  Stocks  in  Citrus  Propa- 
gation. 

Caprifigs  and  Caprification. 

Commercial  Production  of  Grape  Syrup. 

Storage  of  Perishable  Fruit  at  Freezing 
Temperatures. 

Rice  Irrigation  Measurements  and  Ex- 
periments in  Sacramento  Valley, 
1914-1919. 

Prune  Growing  in  California. 

Phylloxera-Resistant  Stocks. 

Preliminary  Volume  Tables  for  Second- 
Growth  Redwood. 

Cocoanut  Meal  as  a  Feed  for  Dairy 
Cows  and  Other  Livestock. 

The  Preparation  of  Nicotine  Dust  as 
an  Insecticide. 

The  Relative  Cost  of  Making  Logs  from 
Small    and   Large   Timber. 

Cheese  Pests  and  Their  Control. 

Cold  Storage  as  an  Aid  to  the  Market- 
ing of  Plums. 


No. 

346. 
347. 

348. 
349. 

350. 
351. 
352. 

353. 
354. 
355. 
357. 


358. 

359. 
360. 

361. 

362. 
363. 

364. 

866. 

367. 

368. 

369. 
370. 
371. 

372. 

373. 
374. 

375. 
376. 


Almond  Pollination. 

The  Control  of  Red  Spiders  in  Decidu- 
ous Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood  Lands. 

California  State  Dairy  Cow  Competition. 

Further  Experiments  in  Plum  Pollina- 
tion. 

Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in   1922. 

The  Peach  Twig  Borer. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
Fungicides. 

Black  Measles,  Water  Berries,  and 
Related   Vine   Troubles. 

Fruit  Beverage  Investigations. 

Gum  Diseases  of  Citrus  Trees  in  Cali- 
fornia. 

Preliminary  Yield  Tables  for  Second 
Growth  Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  to  Mouldy  Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter  Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and  Large  Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

Pear  Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,  1923. 

Sun-Drj^ing  and  Dehydration  of  Wal- 
nuts. 


CIRCULARS 

No.  No. 

70,  Observations    on    the    Status   of    Corn  161. 

Growing  in  California.  164. 

Alfalfa.  165. 

The  Use  of  Lime  and  Gypsum  on  Cali- 
fornia Soils.  166. 

Correspondence  Courses  in  Agriculture.  i67. 

117.  The    Selection    and    Cost    of    a    Small  170! 
Pumping  Plant. 

House  Fumigation.  172. 

The  Control  of  Citrus  Insects.  173. 

Melilotus   indica    as    a    Green-Manure 

Crop  for  California.  174. 

Oidium  or  Powdery  Mildew  of  the  Vine.  178. 

Feeding  and  Management  of  Hogs.  179. 

Some  Observations  on  the  Bulk  Hand- 
ling of  Grain  in   California.  184. 

Announcement  of  the  California  State  190. 

Dairy  Cow  Competition,   1916-18.  193. 

Irrigation  Practice  in  Growing  Small  198. 

Fruit  in  California.  199. 

Bovine  Tuberculosis.  201. 

Control  of  the  Pear  Scab.  202. 

Home  and  Farm  Canning. 

Lettuce  Growing  in  California.  203. 


87 
111 


113. 


127. 
129. 
136. 

144. 
151. 
152. 

153. 

154. 

155. 
157. 
158. 
160. 


Potatoes  in  California. 

Small  Fruit  Culture  in  California. 

Fundamentals   of   Sugar   Beet   Culture 

under  California  Conditions. 
The  County  Farm  Bureau. 
Feeding  Stuffs  of  Minor  Importance. 
Fertilizing  California  Soils  for  the  1918 

Crop. 
Wheat  Culture. 
The    Construction    of    the    Wood-Hoop 

Silo. 
Farm   Drainage  Methods. 
The  Packing  of  Apples  in  California. 
Factors   of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 
A  Flock  of  Sheep  on  the  Farm. 
Agriculture  Clubs   in   California. 
A  Study  of  Farm  Labor  in  California. 
Syrup  from   Sweet  Sorerhum. 
Onion  Growing  in  California. 
Helpful  Hints  to  Hog  Raisers. 
County    Organizations   for   Rural    Fire 

Control. 
Peat  as  a  Manure  Substitute. 


OIROULiARS — OorUinued 


No. 
205. 

206. 
208. 

209. 
210. 
212. 
214. 

215. 
217. 

219. 

220. 
228. 
230. 

231. 

232. 

233. 
234. 

235. 

236. 


237. 

238. 
239. 

240. 

241. 

243. 

244. 
245. 


Blackleg. 

Jack  Cheese. 

Summary  of  the  Annual  Reports  of  the 
Farm  Advisors  of  California. 

The  Function  of  the  Farm  Bureau. 

Suggestions  to  the  Settler  in  California. 

Salvaging  Rain-Damaged  Prunes. 

Seed  Treatment  for  the  Prevention  of 
Cereal  Smuts. 

Feeding  Dairy  Cov^s  in  California. 

Methods  for  Marketing  Vegetables  in 
California. 

The  Present  Status  of  Alkali. 

Unfermented  Fruit  Juices. 

Vineyard  Irrigation   in  Arid  Climates. 

Testing  Milk,  Cream,  and  Skim  Milk 
for  Butterfat. 

The  Home  Vineyard. 

Harvesting  and  Handling  California 
Cherries  for  Eastern  Shipment. 

Artificial  Incubation. 

Winter  Injury  to  Young  Walnut  Trees 
during  1921-22. 

Soil  Analysis  and  Soil  and  Plant  Inter- 
relations. 

The  Common  Hawks  and  Owls  of  Cali- 
fornia from  the  Standpoint  of  the 
Rancher. 

Directions  for  the  Tanning  and  Dress- 
ing of  Furs. 

The  Apricot  in  California. 

Harvesting  and  Handling  Apricots  and 
Plums  for  Eastern  Shipment. 

Harvesting  and  Handling  Pears  for 
Eastern  Shipment. 

Harvesting  and  Handling  Peaches  for 
Eastern   Shipment. 

Marmalade  Juice  and  Jelly  Juice  from 
OitruB  Fruits. 

Central  Wire  Bracing  for  Fruit  Trees. 

Vine  Pruning  Systems. 


No. 

247. 
248. 

249. 
250. 

251. 


252. 
253. 
254. 

255. 

256. 
257. 
258. 
259. 
260. 

261. 
262. 
263. 
264. 

265. 
266. 

267. 

268. 

269. 
270. 
271. 

272. 

273. 

275. 


Colonization  and  Rural  Development. 

Some  Common  Errors  in  Vine  Pruning* 
and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the  Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry    in    California. 

Supports  for  Vines. 

Vineyard   Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil 
izer  in  California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 
to  Irrigation  in  California. 

Sewing  Grain  Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary  Essentials  to  Bovine  Tuber- 
culosis Control. 

Plant  Disease  and  Pest  Control. 

Analyzing  the  Citrus  Orchard  by  Means 
of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;  Causes  and  Remedies. 

Inexpensive  Labor-saving  Poultry  Ap- 
pliances. 

An  Orchard  Brush  Burner. 

A  Farm  Septic  Tank, 

Brooding  Chicks  Artificially. 

California  Farm  Tenancy  and  Methods 
of  Leasing. 

Saving  the  Gophered  Citrus  Tree. 

Marketable  California  Decorative 
Greens. 


